///////////////////////////////////////////////////////////////

//

//	Calculates airmass.

//

//	Copyright (C) 2008 Michael V. Newberry. All Rights Reserved.

//

//	This copyright notice must be included in any portion of this source

//	code that is used in any form and for any purpose.

//



var Site =

{

	'KPNO'	:	'111,35,55,31,57,32',

	'Tucson'	:	'110,56,51,32,14,0',

	'WYNN'	:	'111,36,2,31,57,27',

	'MMTO'	:	'110,53,8,31,41,20',

	'SAO12'	:	'110,52,43.5,31,40,51',

	'Apache'	:	'105,49,14.1,32,46,50',

	'Cloudcroft'	:	'105,44,26,32,57,16.6',

	'Calar'	:	'2,32,56,37,13,19',

	'Boston'	:	'71,03,25,42,21,34',

	'NYC'		:	'73,58,12,49,46,34',

	'Arbor'	:	'83,44,24,42,16,36',

	'Chicaco'	:	'87,37,30,41,52,47',

	'Yerkes'	:	'88,33,22.5,42,34,13.2',

	'Denver'	:	'104,59,23,39,45,22',

	'Albuquerque' :	'106,37,40,35,4,58',

	'Angeles' 	:	'118,14,40,34,3,38',

	'Diego'	:	'117,9,50,32,43,8',

	'Francisco' :	'122,24,20,37,46,43',

	'Vegas'	:	'115,15,0,36,14,0',

	'Austin'	:	'97,45,10,30,17,15',

	'Atlanta'	:	'84,23,50,33,45,10',

	'Toronto'	:	'79,23,21,43,40,07',

	'Montreal'	:	'73,38,25,45,32,57',

	'Winnipeg'	:	'97,8,19,49,53,45',

	'Edmonton'	:	'113,29,38,53,32,27',

	'Vancouver'	:	'123,8,19,49,15,49',

	'Flagstaff'	:	'111,39,6,35,11,58',

	'Phoenix'	:	'112,4,27,33,26,56',

	'Kansas'	:	'94,37,34,39,6,10',

	'Paris'		:	'-2,21,4,48,51,24',

	'London'	:	'0,7,35,51,30,0',

	'Frankfurt'	:	'-8,40,50,50,6,42',

	'Amsterdam':	'-4,53,44,52,22,22',

	'Madrid'	:	'3,42,12,40,25,0',

	'Seoul'	:	'-126,58,57,37,30,55',

	'Sydney'	:	'-151,12,26,-33,52,2',

	'Stromlo'	:	'-149,0,25,-35,19,14',

	'Cape'	:	'-18,25,18,-33,54,58',

	'Gamsberg'	:	'-16,13,27.9,-23,20,34',

	'Munich'	:	'-11,34,49,48,8,21',

	'Rome'	:	'-12,28,56,41,53,44',

	'LaPalma'	:	'17,52,52,28,45,36',

	'Campanas'	:	'70,41,32,-29,0,51',

	'Tololo'	:	'70,48,23,-30,10,9',

	'McDonald'	:	'104,1,23,30,40,17',

	'Siding'	:	'-149,4,3,-31,16,27',

	'Perth'	:	'-115,51,30,-31,57,20',

	'Tokyo'	:	'-139,40,56,35,40,43',

	'Silla'		:	'70,44,19,-29,15,20',

	'PicMidi'	:	'-0,8,27.5,42,56,14',

	'Sutherland'	:	'-20,48,39,-32,22,41',

	'John'		:	'-170,27,50,-43,59,10',

	'Pachon'	:	'70,44,11.8,-30,14,26.3',

	'Haleakala'	:	'156,15,25,20,42,30',

	'Ottawa'	:	'75,41,28,45,25,26',

	'Baltimore'	:	'76,36,52,39,17,41',

	'undef'	:	',,,,,'

};



var _airmass = 1.0;

var _hour_angle = 0.0;

var g_dAngleFuzz = 1.e-8;

var g_dTimeFuzz = 1.e-6;

var g_nDegreeDigits = 2;

var g_nTimeDigits = 1;



var _PT_cSign = '';

var _PT_tSec = 0.0;

var _PT_tHr = 0.0;

var _PT_tMin = 0.0;

var _PD_sSign = '';

var _PD_nYr = 2000.0;

var _PD_nMo = 1.0;

var _PD_nDay = 1.0;

var _PH_cSign = '';

var _PH_tHr = 0.0;

var _PH_tMin = 0.0;

var _PH_tSec = 0.0;

var _PA_cSign = '';

var _PA_tDeg = 0.0;

var _PA_tMin = 0.0;

var _PA_tSec = 0.0;

var _JD_nYr = 0;

var _JD_nMo = 0;

var _JD_nDay = 0;

var _JD_nHr = 0;

var _JD_nMin = 0;

var _JD_dSec = 0.0;



////////////////////////////////////////////////////////////////

function ChooseSite( form )

{

	try

	{

		var sSiteName = Site[ form.SITE.value ];

		sSite = new Array();

		sSite = sSiteName.split(',');

		

		form.LONGD.value = sSite[0];

		form.LONGM.value = sSite[1];

		form.LONGS.value = sSite[2];

		form.LATD.value = sSite[3];

		form.LATM.value = sSite[4];

		form.LATS.value = sSite[5];

	}

	catch( error )

	{

		form.LONGD.value = '';

		form.LONGM.value = '';

		form.LONGS.value = '';

		form.LATD.value = '';

		form.LATM.value = '';

		form.LATS.value = '';

	}

}



////////////////////////////////////////////////////////////////

function FormatDateStr( syr, smo, sday )

{

	var yr = Math.floor( Number(syr) );

	if ( yr < 10 )

	{

		if ( yr != 0 )

			yr += 2000;

		else

			yr = 2000;

	}

	return sprintf( '%04d-%02d-%02d', yr, Number(smo), Number(sday) );

}



////////////////////////////////////////////////////////////////

function FormatTimeStr( h, m, s )

{

	var sh = '';

	if ( h == 0 )

		sh = '0';

	else

		sh = String(h);

	var sign = '';

	if ( sh.charAt(0) == '-' )

		sign = '-';

	var nh = Number(sh);

	var nm = Number(m)

	var ds = Number(s);

	

	var sTimeFmt = sprintf('%%s%%02d:%%02d:%%0%d.%df', g_nTimeDigits+3, g_nTimeDigits );

	var dRound = Math.pow( 10.0, -g_nTimeDigits ) / 2.0;	// seconds

	return sprintf( sTimeFmt, sign, Math.abs(nh), nm, Math.floor(ds+dRound) );

}



////////////////////////////////////////////////////////////////

function FormatDateTimeStr( syr, smo, sday, sh, sm, ss )

{

	var yr = Math.floor( Number(syr) );

	if ( yr < 10 )

	{

		if ( yr != 0 )

			yr += 2000;

		else

			yr = 2000;

	}

	

	var sDateTimeFmt = sprintf('%%04d-%%02d-%%02dT%%02d:%%02d:%%0%d.%df', g_nTimeDigits+3, g_nTimeDigits );

	var dRound = Math.pow( 10.0, -g_nTimeDigits ) / 2.0;	// seconds

	return sprintf( sDateTimeFmt, yr, smo, sday, sh, sm, Math.floor( Number(ss) + dRound ) );

}



////////////////////////////////////////////////////////////////

function FormatDegreeStr( d, m, s )

{

	var sd = '';

	if ( d == 0 )

		sd = '0';

	else

		sd = String(d);

	var sign = '';

	if ( sd.charAt(0) == '-' )

		sign = '-';

	var nd = Number(sd);

	var nm = Number(m)

	var ds = Number(s);



	var sDegreeFmt = sprintf( '%%s%%02d:%%02d:%%0%d.%df', g_nDegreeDigits+3, g_nDegreeDigits );

	var dRound = Math.pow( 10.0, -g_nTimeDigits ) / 2.0;	// seconds

	return sprintf( sDegreeFmt, sign, Math.abs(nd), nm, Math.floor( ds + dRound ) );

}



/////////////////////////////////////////////////////////////////////////

function Airmass( sRa, sDec, sLong, sLat, sDate, sTime  )

{

	_airmass = 0;



	var dRa = ParseHours( sRa );

	var dDec = ParseDegrees( sDec );

	var dLat = ParseDegrees( sLat );



	var dHa = 15.0 * ( (CalcLocalSiderealTime( sDate, sTime, sLong ) - dRa + 24) % 24 );

	_hour_angle = dHa;

	

	var dCosZ = ( Math.sin(ToRadians(dLat)) * Math.sin(ToRadians(dDec)) ) + ( Math.cos(ToRadians(dLat)) * Math.cos(ToRadians(dDec)) * Math.cos(ToRadians(dHa)) );



	if ( dCosZ > 0.0 && dCosZ <= 1.0 )

	{

		var dSecZ = 1.0 / dCosZ;

		var dZ = ToDegrees( Math.acos( dCosZ ) );

		_airmass = 1.0 / (dCosZ + 0.50572 * Math.pow( 96.07995 - dZ, -1.6364 ));

	}

	else

		_airmass = 0.0;



	return _airmass;

}



/////////////////////////////////////////////////////////////////////////

function CalcLocalSiderealTime( sDate, sTime, sLong )

{

	ParseDate( sDate );

	var dTime = ParseHours( sTime );



	var dA = 0.0657098;

	var dC = 1.00273790935;

	var dD = 0.997270;



	var sYear0 = sprintf( '%04d-01-01', _PD_nYr );

	var dJdJan0 = JulianDay( sYear0, '00:00:00.0' ) - 1;



	var s = dJdJan0 - 2415020.0;

	var t = s / 36525.0;

	var r = 6.6460656 + (2400.051262 * t) + (0.00002581 * t * t);

	var u = r - (24 * (_PD_nYr - 1900));

	var dB = 24.0 - u;



	var dJd = JulianDay( sDate, '00:00:00.0' );



	var dDays = dJd - dJdJan0;

	var dT0 = dA * dDays - dB;



	var dGST = ((ParseHours( sTime ) * dC) + dT0 + 48) % 24;



	var dLongHrs = ParseDegrees( sLong ) / 15.0;

	return (dGST - dLongHrs + 48) % 24;

}



///////////////////////////////////////////////////////////////////////////////

function JulianDay( sDate, sTime )

{

	ParseDate( sDate );



	var y = Math.floor( (_PD_nMo > 2) ? _PD_nYr : _PD_nYr - 1 );

	var j = Math.floor( (_PD_nMo > 2) ? _PD_nMo - 3 : _PD_nMo + 9 );



	var a = Math.floor( 146097.0 * Math.floor( (y + 2000) / 100 ) / 4 ) + 990634.0;

	var b = Math.floor( 1461.0 * ((y + 2000) % 100) / 4 );

	var c = Math.floor((153 * j + 2) / 5) + _PD_nDay;



	ParseTime( sTime );



	return (a + b + c + _PT_tHr/24.0 + _PT_tMin/1440.0 + _PT_tSec/86400.0 - 0.5);

}



///////////////////////////////////////////////////////////////////////////////

function ParseJulianDay( dJulianDay )

{

	var dRound = Math.pow( 10.0, -g_nTimeDigits ) / 2.0;	// seconds

	

	var dSecRounded = 0.0;

	var nCounter = 1;

	var nMaxLoops = 3;

	

	_JD_nYr = 0;

	_JD_nMo = 0;

	_JD_nDay = 0;

	_JD_nHr = 0;

	_JD_nMin = 0;

	_JD_dSec = 0.0;



	do

	{

		var dJD = dJulianDay + 0.5;

		var dI = Math.floor( dJD );

		var dF = dJD - dI;

	

		var dA = 0.0;

		var dB = 0.0;

	

		if ( dI > 2299160.0 )

		{

			dA = Math.floor( (dI - 1867216.25) / 36524.25 );

			dB = dI + 1.0 + dA - Math.floor( dA / 4.0 );

		}

		else

		{

			dA = dI;

			dB = 0.0;

		}

	

		var dC = dB + 1524.0;

		

		var dD = Math.floor( (dC - 122.1) / 365.25 );

		var dE = Math.floor( 365.25 * dD );

		var dG = Math.floor( (dC - dE) / 30.6001 );

	

		var dDay = dC - dE + dF - Math.floor( 30.6001 * dG );

		_JD_nDay = Math.floor( dDay );

	

		var dM = 0.0;

		if ( dG < 13.5 )

			dM = dG - 1.0;

		else

			dM = dG - 13.0;

		_JD_nMo = Math.floor( dM );	// month

	

		var dY = 0.0;

		if ( dM > 2.5 )

			dY = dD - 4716.0;

		else

			dY = dD - 4715.0;

		_JD_nYr = Math.floor( dY );	// year



		var dHr = (dDay - _JD_nDay) * 24.0;

		_JD_nHr = Math.floor( dHr );	// hour

		var dMin = (dHr - _JD_nHr) * 60.0;

		_JD_nMin = Math.floor( dMin );	// minute

		_JD_dSec = (dMin - _JD_nMin) * 60.0;	// second

	

		dSecRounded = _JD_dSec + dRound;

		if ( dSecRounded >= 60.0 )

			dJulianDay += (60.0 - _JD_dSec + g_dTimeFuzz) / 86400.0;

			

	} while ( nCounter++ < nMaxLoops && dSecRounded >= 60.0 );

}



///////////////////////////////////////////////////////////////////////////////

function ToRadians( degrees )

{

	return degrees * Math.PI / 180.0;

}



///////////////////////////////////////////////////////////////////////////////

function ToDegrees( radians )

{

	return radians * 180.0 / Math.PI;

}



////////////////////////////////////////////////////////////////////////////

// converts sHours to hours, minutes, seconds.

// returns the number of decimal hours

function ParseHours( sHours )

{

	_PH_cSign = '';

	_PH_tHr = 0;

	_PH_tMin = 0;

	_PH_tSec = 0;



	if ( sHours.length < 1 )

		return 0;



	var d = new Array();

	d[0] = 0;

	d[1] = 0;

	d[2] = 0;



	var bNegative = false;

	if ( sHours.charAt(0) == '-' )

		bNegative = true;



	var tok = new strtok( sHours, '/-:, HhMmSs\"\'' );

	var substr = '';

	var i = 0;

	while ( (substr = tok.next()) != '' )

		d[i++] = Math.abs( Number(substr) ) ;



	var dHours = d[0] + (d[1] + d[2]/60.0) / 60.0;

	var dMin = 0;

	

	if ( bNegative == true )

	{

		dHours = -dHours;



		_PH_tHr  = Math.ceil( dHours );

		dMin = (dHours - _PH_tHr) * 60.0 + g_dAngleFuzz;

		_PH_tMin = Math.ceil( dMin );

		_PH_tSec = (dMin - _PH_tMin) * 60.0 + g_dAngleFuzz;

		_PH_cSign = '-';

	}

	else

	{

		_PH_tHr  = Math.floor( dHours );

		dMin = (dHours - _PH_tHr) * 60.0 + g_dAngleFuzz;



		_PH_tMin = Math.floor( dMin );

		_PH_tSec = (dMin - _PH_tMin) * 60.0 + g_dAngleFuzz;

		_PH_cSign = '+';

	}



	return dHours;

}



////////////////////////////////////////////////////////////////////////////

function ParseDate( sDate )

{

	_PD_sSign = '';

	_PD_nYr = 2000.0;

	_PD_nMo = 1.0;

	_PD_nDay = 1.0;



	var d = new Array();

	d[0] = 2000.0;

	d[1] = 1.0;

	d[2] = 1.0;



	if ( sDate.charAt(0) == '-' )

		_PD_sSign = '-';



	var tok = new strtok( sDate, 'T/-:, YyMmDd' );

	var substr = '';

	var i = 0;

	while ( (substr = tok.next()) != '' )

		d[i++] = Number(substr);



	if ( d[0] >= 1000.0 )

	{

		_PD_nYr = d[0];

		_PD_nMo = d[1];

		_PD_nDay = d[2];

	}

	else if ( d[2] >= 1000.0 )

	{

		_PD_nYr = d[2];

		_PD_nMo = d[1];

		_PD_nDay = d[0];

	}

	else

	{

		_PD_nYr = 1900.0+ d[2];

		_PD_nMo = d[1];

		_PD_nDay = d[0];

	}

}



/////////////////////////////////////////////////////////////////////////////

// returns seconds

function ParseTime( sTime0 )

{

	_PT_cSign = '';

	_PT_tHr = 0;

	_PT_tMin = 0;

	_PT_tSec = 0;

	

	var sTime = sTime0;

	var ss = new Array();

	ss = sTime0.split( 'T' );	

	if ( ss.length > 1 )

		sTime = ss[1];



	if ( sTime.length < 1 )

		return 0;



	var d = new Array();

	d[0] = 0;

	d[1] = 0;

	d[2] = 0;



	var bNegative = false;

	if ( sTime.charAt(0) == '-' )

		bNegative = true;



	var tok = new strtok( sTime, '/-:, HhMmSs\"\'' );

	var substr = '';

	var i = 0;

	while ( (substr = tok.next()) != '' )

		d[i++] = Math.abs( Number(substr) ) ;



	var dHours = d[0] + (d[1] + d[2]/60.0) / 60.0;

	var dMin = 0;

	

	if ( bNegative == true )

	{

		dHours = -dHours;



		_PT_tHr  = Math.ceil( dHours );

		dMin = (dHours - _PT_tHr) * 60.0 + g_dAngleFuzz;

		_PT_tMin = Math.ceil( dMin );

		_PT_tSec = (dMin - _PT_tMin) * 60.0 + g_dAngleFuzz;

		_PT_cSign = '-';

	}

	else

	{

		_PT_tHr  = Math.floor( dHours );

		dMin = (dHours - _PT_tHr) * 60.0 + g_dAngleFuzz;



		_PT_tMin = Math.floor( dMin );

		_PT_tSec = (dMin - _PT_tMin) * 60.0 + g_dAngleFuzz;

		_PT_cSign = '+';

	}



	return dHours;

}



////////////////////////////////////////////////////////////////////////////

// converts an angle string to degrees, minutes, seconds, and decimal degrees

function ParseDegrees( sDeg )

{

	_PA_cSign = '+';

	_PA_tDeg = 0;

	_PA_tMin = 0;

	_PA_tSec = 0.0;

	

	var d = new Array();

	d[0] = 0;

	d[1] = 0;

	d[2] = 0;



	var bNegative = false;

	if ( sDeg.charAt(0) == '-' )

		bNegative = true;

	

	var tok = new strtok( sDeg, '/-:, DdMmSs\"\'\xb0' );

	var substr = '';

	var i = 0;

	while ( (substr = tok.next()) != '' )

		d[i++] = Math.abs( Number(substr) );



	var dDegrees = d[0] + (d[1] + d[2] / 60.0) / 60.0;

	var dMin = 0;

	

	if ( bNegative == true )

	{

		dDegrees = -dDegrees;



		_PA_tDeg  = Math.ceil( dDegrees );

		dMin = (dDegrees - _PA_tDeg) * 60.0 + g_dAngleFuzz;



		_PA_tMin = Math.ceil( dMin );

		_PA_tSec = (dMin - _PA_tMin) * 60.0 + g_dAngleFuzz;



		_PA_cSign = '-';

	}

	else

	{

		_PA_tDeg  = Math.floor( dDegrees );

		dMin = (dDegrees - _PA_tDeg) * 60.0 + g_dAngleFuzz;



		_PA_tMin = Math.floor( dMin );

		_PA_tSec = (dMin - _PA_tMin) * 60.0 + g_dAngleFuzz;



		_PA_cSign = '+';

	}



	return dDegrees;

}



////////////////////////////////////////////////////////////////////////////

function TimeToStr( time_val )

{

	var positive = '+';

	if ( time_val < 0 )

	{

		positive = '-';

		time_val = -time_val;

	}



	var n0 = Math.floor( time_val );

	var d1 = (time_val - n0) * 60.0 + g_dAngleFuzz;

	var n2 = Math.floor( d1 );

	var d3 = (d1 - n2) * 60.0 + g_dAngleFuzz;



	var sTimeFmt = sprintf('%%s%%02d:%%02d:%%0%d.%df', g_nTimeDigits+3, g_nTimeDigits );

	var str = sprintf( sTimeFmt, positive, n0, n2, d3 );

	return str;

}



////////////////////////////////////////////////////////////////////

function Message( msg, form )

{

	var w = 400;

	var h = 150;

	var pos = sprintf( 'left=%d,top=%d,width=%d,height=%d', window.event.screenX-w/2, window.event.screenY-h/2, w, h );

	var generator=window.open( '', 'MsgWin', pos );



	generator.document.write( '<html><head><title>Airmass Planner Message</title>' );

	generator.document.write( '<link rel="stylesheet" href="styles/mirametrics.css">' );

	generator.document.write( '</head><body>' );

	generator.document.write( '<br><p class="norm150">' );

	generator.document.write( msg );

	generator.document.write( '</p>' );



	generator.document.write( '</body></html>' );

	generator.document.close();

}



////////////////////////////////////////////////////////////////////

function CalcAirmassTable( form )

{

	form.result.value = '';



	var sRa = FormatTimeStr( form.RAH.value, form.RAM.value, form.RAS.value );

	var sDec = FormatDegreeStr( form.DECD.value, form.DECM.value, form.DECS.value );

	var sLong = FormatDegreeStr( form.LONGD.value, form.LONGM.value, form.LONGS.value );	// assume West longitude > 0

	var sLat = FormatDegreeStr( form.LATD.value, form.LATM.value, form.LATS.value );

	var sDateStart = FormatDateStr( form.DATESY.value, form.DATESM.value, form.DATESD.value );

	var sTimeStart = FormatTimeStr( form.TIMESH.value, form.TIMESM.value, form.TIMESS.value );

	var sDateEnd = FormatDateStr( form.DATEEY.value, form.DATEEM.value, form.DATEED.value );

	var sTimeEnd = FormatTimeStr( form.TIMEEH.value, form.TIMEEM.value, form.TIMEES.value );

	var sTimeInt = FormatTimeStr( form.TIMEIH.value, form.TIMEIM.value, form.TIMEIS.value );

	

	var SEP = String(form.SEP.value);

	var sSep = ' ';

	if ( SEP.length > 0 )

		sSep = SEP.charAt(0);



	var sObject = form.OBJECT.value;

	var sFmtObj = '%s';

	var sObj = '';

	var sObjTitle = '';

	if ( sObject.length > 0 )

	{

		var len = Math.min( Math.max( 7, sObject.length ), 19 );

		var sFmtName = sprintf( '%%-%d.%ds%%s', len, len );

		sObjTitle = sprintf( sFmtName, 'Object', sSep );

		sObj = sprintf( sFmtName, sObject, sSep );

	}

		

	var dJdStart = JulianDay( sDateStart, sTimeStart );

	var dJdEnd = JulianDay( sDateEnd, sTimeEnd );

	if ( dJdEnd < dJdStart )

	{

		dJdEnd += 1.0;

	}

	dJdEnd -= dJdStart;

	var dStep = Math.max( ParseHours( sTimeInt ), 0 ) / 24.0;



	if ( dStep < 1.0 / (24*60*60) )

		dStep = dJdEnd;

	if ( dJdEnd < 1.e-5 )

		dStep = 1.0;



	var sFmtStr0 = '%%s %%-10.10s%%s %%-%d.%ds%%s %%-9s%%s %%-%d.%ds\n';

	var sFmtStr = sprintf(sFmtStr0, g_nTimeDigits+9, g_nTimeDigits+9, g_nTimeDigits+10, g_nTimeDigits+10 );

	

	var sHdr = sprintf( sFmtStr, sObjTitle, 'Date (UT)', sSep, 'Time (UT)', sSep, 'Airmass', sSep, 'Hour Angle' );

	var out = sHdr;



	for ( var t = 0.0; t <= dJdEnd + g_dTimeFuzz; t+=dStep )

	{

		ParseJulianDay( t + dJdStart );

		var sDate = FormatDateStr( _JD_nYr, _JD_nMo, _JD_nDay );

		var sTime = FormatTimeStr( _JD_nHr, _JD_nMin, _JD_dSec );

		var dAirmass = Airmass( sRa, sDec, sLong, sLat, sDate, sTime );

		var sHa = TimeToStr( (_hour_angle / 15.0 + 12.0) % 24.0 - 12.0 );



		var sX = '';

		if ( dAirmass >= 0.5 )

		{

			if ( dAirmass >= 20.0 )

				sX = sprintf( '%-8.8s', '@Horizon' );

			else if ( dAirmass >= 1.0 )

				sX = sprintf( '%-8.4f', dAirmass );

			else

				sX = sprintf( '%-8.4f', 1.0 );

		}

		else

			sX = sprintf( '%-8.8s', '<Horizon' );

		str = sprintf( sFmtStr, sObj, sDate, sSep, sTime, sSep, sX, sSep, sHa );

		out += str;

	}

	form.result.value = out;

}



////////////////////////////////////////////////////////////////////

function ClearInputsTable( form )

{

	form.RAH.value= '';

	form.RAM.value= '';

	form.RAS.value= '';

	form.DECD.value= '';

	form.DECM.value= '';

	form.DECS.value= '';

	form.OBJECT.value = '';



	if ( form.SITE.value == 'undefined' )

	{

		form.LONGD.value='';

		form.LONGM.value='';

		form.LONGS.value='';

		form.LATD.value='';

		form.LATM.value='';

		form.LATS.value='';

	}



	form.DATESY.value = '';

	form.DATESM.value = '';

	form.DATESD.value = '';

	form.DATEEY.value = '';

	form.DATEEM.value = '';

	form.DATEED.value = '';

	

	form.TIMESH.value = '';

	form.TIMESM.value = '';

	form.TIMESS.value = '';

	form.TIMEEH.value = '';

	form.TIMEEM.value = '';

	form.TIMEES.value = '';

	form.TIMEIH.value = '';

	form.TIMEIM.value = '';

	form.TIMEIS.value = '';

}



////////////////////////////////////////////////////////////////

function GetDateTimeNowTable( form )

{

	var dt = new Date();



	form.DATESY.value = dt.getUTCFullYear();

	form.DATESM.value = dt.getUTCMonth() + 1;

	form.DATESD.value = dt.getUTCDate();

	form.DATEEY.value = dt.getUTCFullYear();

	form.DATEEM.value = dt.getUTCMonth() + 1;

	form.DATEED.value = dt.getUTCDate();

	

	form.TIMESH.value = dt.getUTCHours();

	form.TIMESM.value = dt.getUTCMinutes();

	form.TIMESS.value = dt.getUTCSeconds();

	form.TIMEEH.value = dt.getUTCHours();

	form.TIMEEM.value = dt.getUTCMinutes();

	form.TIMEES.value = dt.getUTCSeconds();

}



////////////////////////////////////////////////////////////////

function GetDateTimeTonight( form )

{

	var dStep = 5 / 24.0;	// days before and after midnight

	

	var dt = new Date();

	var sDate = FormatDateStr( dt.getUTCFullYear(), dt.getUTCMonth() + 1, dt.getUTCDate() );

	var sTime = FormatTimeStr( dt.getUTCHours(), dt.getUTCMinutes(), dt.getUTCSeconds() );

	var dJd = Math.floor( JulianDay( sDate, sTime ) ) + 0.5;

		

	var sLong = FormatDegreeStr( form.LONGD.value, form.LONGM.value, form.LONGS.value );

	var dLongHrs = Math.floor( ParseDegrees( sLong ) / 15.0 );

	var dUTDiff = ((dLongHrs + 24) % 24) / 24.0;



	var dJdBefore = dJd + dUTDiff  - dStep;

	ParseJulianDay( dJdBefore );

	form.DATESY.value = _JD_nYr;

	form.DATESM.value = _JD_nMo;

	form.DATESD.value = _JD_nDay;

	form.TIMESH.value = _JD_nHr;

	form.TIMESM.value = 0;

	form.TIMESS.value = 0;

	

	var dJdAfter = dJd + dUTDiff + dStep;

	ParseJulianDay( dJdAfter );

	form.DATEEY.value = _JD_nYr;

	form.DATEEM.value = _JD_nMo;

	form.DATEED.value = _JD_nDay;

	form.TIMEEH.value = _JD_nHr;

	form.TIMEEM.value = 0;

	form.TIMEES.value = 0;

	

	form.TIMEIH.value = 1;

	form.TIMEIM.value = 0;

	form.TIMEIS.value = 0;

}



/////////////////////////////////////////////////////////////////////////

function SaveCookie()

{

	var form = document.forms['airmass'];

	if ( form == null )

		return;

	

	var dt = new Date();

	expires = sprintf( '%d,%d,%d', dt.getUTCFullYear() + 10, dt.getUTCMonth(), dt.getUTCDate() );



	var str = 

	form.elements['RAH'].value + '^' +

	form.elements['RAM'].value + '^' +

	form.elements['RAS'].value + '^' +

	form.elements['DECD'].value + '^' +

	form.elements['DECM'].value + '^' +

	form.elements['DECS'].value + '^' +

	

	form.elements['OBJECT'].value + '^' +

	form.elements['SITE'].value + '^' +

	

	form.elements['LONGD'].value + '^' +

	form.elements['LONGM'].value + '^' +

	form.elements['LONGS'].value + '^' +

	form.elements['LATD'].value + '^' +

	form.elements['LATM'].value + '^' +

	form.elements['LATS'].value + '^' +



	form.elements['DATESY'].value + '^' +

	form.elements['DATESM'].value + '^' +

	form.elements['DATESD'].value + '^' +

	form.elements['TIMESH'].value + '^' +

	form.elements['TIMESM'].value + '^' +

	form.elements['TIMESS'].value + '^' +



	form.elements['DATEEY'].value + '^' +

	form.elements['DATEEM'].value + '^' +

	form.elements['DATEED'].value + '^' +

	form.elements['TIMEEH'].value + '^' +

	form.elements['TIMEEM'].value + '^' +

	form.elements['TIMEES'].value + '^' +



	form.elements['TIMEIH'].value + '^' +

	form.elements['TIMEIM'].value + '^' +

	form.elements['TIMEIS'].value + '^' +



	form.elements['SEP'].value;



	var sCookieName = window.location.pathname;

	_delete_cookie( sCookieName );

	_set_cookie( sCookieName, str, expires );

}



/////////////////////////////////////////////////////////////////////////

function LoadCookie()

{

	var form = document.forms['airmass'];

	if ( form == null )

		return;



	var sCookieName = window.location.pathname;	

	

	var sCookie = _get_cookie( sCookieName );

	if ( sCookie )

	{

		var ca = sCookie.split('^');

		if ( ca.length == 30 )

		{

			form.elements['RAH'].value = ca[0];

			form.elements['RAM'].value = ca[1];

			form.elements['RAS'].value = ca[2];

			form.elements['DECD'].value = ca[3];

			form.elements['DECM'].value = ca[4];

			form.elements['DECS'].value = ca[5];

			

			form.elements['OBJECT'].value = ca[6];

			form.elements['SITE'].value = ca[7];

			

			form.elements['LONGD'].value = ca[8];

			form.elements['LONGM'].value = ca[9];

			form.elements['LONGS'].value = ca[10];

			form.elements['LATD'].value = ca[11];

			form.elements['LATM'].value = ca[12];

			form.elements['LATS'].value = ca[13];

		

			form.elements['DATESY'].value = ca[14];

			form.elements['DATESM'].value = ca[15];

			form.elements['DATESD'].value = ca[16];

			form.elements['TIMESH'].value = ca[17];

			form.elements['TIMESM'].value = ca[18];

			form.elements['TIMESS'].value = ca[19];

		

			form.elements['DATEEY'].value = ca[20];

			form.elements['DATEEM'].value = ca[21];

			form.elements['DATEED'].value = ca[22];

			form.elements['TIMEEH'].value = ca[23];

			form.elements['TIMEEM'].value = ca[24];

			form.elements['TIMEES'].value = ca[25];

			

			form.elements['TIMEIH'].value = ca[26];

			form.elements['TIMEIM'].value = ca[27];

			form.elements['TIMEIS'].value = ca[28];

	

			form.elements['SEP'].value = ca[29];

			

			//window.status="Your default settings were loaded";

			return;

		}

	}



	form.elements['RAH'].value = '';

	form.elements['RAM'].value = '';

	form.elements['RAS'].value = '';

	form.elements['DECD'].value = '';

	form.elements['DECM'].value = '';

	form.elements['DECS'].value = '';

	

	form.elements['OBJECT'].value = '';

	form.elements['SITE'].value = 'undef';

	

	form.elements['LONGD'].value = '';

	form.elements['LONGM'].value = '';

	form.elements['LONGS'].value = '';

	form.elements['LATD'].value = '';

	form.elements['LATM'].value = '';

	form.elements['LATS'].value = '';



	form.elements['DATESY'].value = '';

	form.elements['DATESM'].value = '';

	form.elements['DATESD'].value = '';

	form.elements['TIMESH'].value = '';

	form.elements['TIMESM'].value = '';

	form.elements['TIMESS'].value = '';



	form.elements['DATEEY'].value = '';

	form.elements['DATEEM'].value = '';

	form.elements['DATEED'].value = '';

	form.elements['TIMEEH'].value = '';

	form.elements['TIMEEM'].value = '';

	form.elements['TIMEES'].value = '';

	

	form.elements['TIMEIH'].value = '';

	form.elements['TIMEIM'].value = '';

	form.elements['TIMEIS'].value = '';



	form.elements['SEP'].value = '';

}