//Global variables
var winCal;
var dtToday=new Date();
var Cal;
var docCal;
var MonthName=["January", "February", "March", "April", "May", "June","July", 
	"August", "September", "October", "November", "December"];
var WeekDayName=["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];	
var exDateTime;//Existing Date and Time

//Configurable parameters
var cnTop="200";//top coordinate of calendar window.
var cnLeft="500";//left coordinate of calendar window
var WindowTitle ="Select Date";//Date Time Picker title.
var WeekChar=2;//number of character for week day. if 2 then Mo,Tu,We. if 3 then Mon,Tue,Wed.
var CellWidth=20;//Width of day cell.
var DateSeparator="/";//Date Separator, you can change it to "/" if you want.
var TimeMode=24;//default TimeMode value. 12 or 24

var ShowLongMonth=true;//Show long month name in Calendar header. example: "January".
var ShowMonthYear=true;//Show Month and Year in Calendar header.
var MonthYearColor="#cc0033";//Font Color of Month and Year in Calendar header.
var MonthYearColor="#666666";//Font Color of Month and Year in Calendar header.
var WeekHeadColor="#ffffff";//Background Color in Week header.
var SundayColor="#CCCCFF";//Background color of Sunday.
var SaturdayColor="#CCCCFF";//Background color of Saturday.
var WeekDayColor="white";//Background color of weekdays.
var FontColor="blue";//color of font in Calendar day cell.
var TodayColor="#66FF33";//Background color of today.
var SelDateColor="#FFFF99";//Backgrond color of selected date in textbox.
var YrSelColor="#cc0033";//color of font of Year selector.
var CalBg="#cccccc";//Background color of Calendar window.
//var ThemeBg="#999999";//Background image of Calendar window.
//end Configurable parameters
//end Global variable


/*---------------------------------*/
function NewCal(pCtrl,pFormat)
{

	Cal=new Calendar(dtToday);	
	if (pCtrl!=null)
		Cal.Ctrl=pCtrl;
	if (pFormat!=null)
		Cal.Format=pFormat.toUpperCase();
	
	exDateTime=document.getElementById(pCtrl).value;
	if (exDateTime!="" && exDateTime.toUpperCase()!=Cal.Format)//Parse Date String
	{
		var Sp1;//Index of Date Separator 1
		var Sp2;//Index of Date Separator 2 
		var strMonth;
		var strDate;
		var strYear;
		var intMonth;
		var YearPattern;

		//parse month
		Sp1=exDateTime.indexOf(DateSeparator,0)
		Sp2=exDateTime.indexOf(DateSeparator,(parseInt(Sp1)+1));
		
		if ((Cal.Format.toUpperCase()=="DDMMYYYY") || (Cal.Format.toUpperCase()=="DDMMMYYYY"))
		{
			strMonth=exDateTime.substring(Sp1+1,Sp2);
			strDate=exDateTime.substring(0,Sp1);
		}
		else if ((Cal.Format.toUpperCase()=="MMDDYYYY") || (Cal.Format.toUpperCase()=="MMMDDYYYY"))
		{
			strMonth=exDateTime.substring(0,Sp1);
			strDate=exDateTime.substring(Sp1+1,Sp2);
		}
		else if ((Cal.Format.toUpperCase()=="MMDDYY"))
		{
			strMonth=exDateTime.substring(0,Sp1);
			strDate=exDateTime.substring(Sp1+1,Sp2);
		}
		else if ((Cal.Format.toUpperCase()=="MM-DD-YY"))
		{
			strMonth=exDateTime.substring(0,Sp1);
			strDate=exDateTime.substring(Sp1+1,Sp2);
		}
		else if ((Cal.Format.toUpperCase()=="MM/DD/YY"))
		{
			strMonth=exDateTime.substring(0,Sp1);
			strDate=exDateTime.substring(Sp1+1,Sp2);
		}


		if (isNaN(strMonth))
			intMonth=Cal.GetMonthIndex(strMonth);
		else
			intMonth=parseInt(strMonth,10)-1;	
		if ((parseInt(intMonth,10)>=0) && (parseInt(intMonth,10)<12))
			Cal.Month=intMonth;
		//end parse month

		//parse Date
		if ((parseInt(strDate,10)<=Cal.GetDaysInMonth()) && (parseInt(strDate,10)>=1))
			Cal.Date=strDate;
		//end parse Date

		//parse year
		strYear=exDateTime.substring(Sp2+1,Sp2+5);
		YearPattern=/^\d{4}$/;
		if (YearPattern.test(strYear))
			Cal.Year=parseInt(strYear,10);
		YearPattern=/^\d{2}$/;
		if (YearPattern.test(strYear)){
			var year = parseInt(strYear,10);
			if(year < 60){
				Cal.Year= 2000 + year;
			}
			if(year >= 60){
				Cal.Year= 1900 + year;
			}
		}
		//end parse year
		
		/*
		alert("exdate:" + exDateTime + "\n" 
			+ "Cal.Month:" + Cal.Month + "\n" 
			+ "Cal.Date:" + Cal.Date + "\n" 
			+ "Cal.Year:" + Cal.Year + "\n" 
		);
		*/	
	}
	winCal=window.open("","SelectDate","toolbar=0,status=0,menubar=0,fullscreen=no,width=200,height=245,resizable=1,top="+cnTop+",left="+cnLeft);
	docCal=winCal.document;
	RenderCal();
}


/*---------------------------------*/
function RenderCal()
{
	var vCalHeader;
	var vCalData;
	var vCalTime;
	var i;
	var j;
	var SelectStr;
	var vDayCount=0;
	var vFirstDay;

	docCal.open();
	docCal.writeln("<html><head><title>"+WindowTitle+"</title>");
	docCal.writeln("<script>var winMain=window.opener;</script>");
	docCal.writeln("</head><body bgcolor='"+CalBg+"' link="+FontColor+" vlink="+FontColor+"><form name='Calendar'>");

	vCalHeader="<table style='border:black solid 1px;border-collapse:collapse;' border=1 cellpadding=2 cellspacing=0 width='100%' align=\"center\" valign=\"top\">\n";
	//Month Selector
	vCalHeader+="<tr>\n<td colspan='7'><table border=0 width='100%' cellpadding=0 cellspacing=0><tr><td align='left'>\n";
	vCalHeader+="<select name=\"MonthSelector\" onChange=\"javascript:winMain.Cal.SwitchMth(this.selectedIndex);winMain.RenderCal();\">\n";
	for (i=0;i<12;i++)
	{
		if (i==Cal.Month)
			SelectStr="Selected";
		else
			SelectStr="";	
		vCalHeader+="<option "+SelectStr+" value >"+MonthName[i]+"\n";
	}
	vCalHeader+="</select></td>";


	//Year selector
	//vCalHeader+="\n<td align='right'><a href=\"javascript:winMain.Cal.DecYear();winMain.RenderCal()\"><b><font color=\""+YrSelColor+"\"><</font></b></a><font face=\"Verdana\" color=\""+YrSelColor+"\" size=2><b> "+Cal.Year+" </b></font><a href=\"javascript:winMain.Cal.IncYear();winMain.RenderCal()\"><b><font color=\""+YrSelColor+"\">></font></b></a></td></tr></table></td>\n";	
	vCalHeader+="<td align='right'><select name=\"YearSelector\" onChange=\"javascript:winMain.Cal.SwitchYr(this.selectedIndex);winMain.RenderCal();\">\n";
	for (i=1960;i<2010;i++)
	{
		if (i==Cal.Year)
			SelectStr="Selected";
		else
			SelectStr="";	
		vCalHeader+="<option "+SelectStr+" value >"+i+"\n";
	}
	vCalHeader+="</select>";
	vCalHeader+="</td></tr></table></td></tr>";

	//Calendar header shows Month and Year
	if (ShowMonthYear)
		vCalHeader+="<tr><td colspan='7'><font face='Verdana' size='2' align='center' color='"+MonthYearColor+"'><b>"+Cal.GetMonthName(ShowLongMonth)+" "+Cal.Year+"</b></font></td></tr>\n";
	//Week day header
	vCalHeader+="<tr bgcolor="+WeekHeadColor+">";
	for (i=0;i<7;i++)
	{
		vCalHeader+="<td style='border:black solid 1px;' align='center'><font face='Verdana' size='2'>"+WeekDayName[i].substr(0,WeekChar)+"</font></td>";
	}
	vCalHeader+="</tr>";	
	docCal.write(vCalHeader);
	
	//Calendar detail
	CalDate=new Date(Cal.Year,Cal.Month);
	CalDate.setDate(1);
	vFirstDay=CalDate.getDay();
	vCalData="<tr>";

	for (i=0;i<vFirstDay;i++)
	{
		vCalData=vCalData+GenCell();
		vDayCount=vDayCount+1;
	}
	for (j=1;j<=Cal.GetDaysInMonth();j++)
	{
		var strCell;
		vDayCount=vDayCount+1;

		if ( (j==dtToday.getDate())&&
			 (Cal.Month==dtToday.getMonth())&&
			 (Cal.Year==dtToday.getFullYear())){
			strCell=GenCell(j,true,TodayColor); //Highlight today's date
		}
		else
		{
			if (j==Cal.Date)
			{
				strCell=GenCell(j,true,SelDateColor);
			}
			else
			{	 
				if (vDayCount%7==0)
					strCell=GenCell(j,false,SaturdayColor);
				else if ((vDayCount+6)%7==0)
					strCell=GenCell(j,false,SundayColor);
				else
					strCell=GenCell(j,null,WeekDayColor);
			}		
		}						
		vCalData=vCalData+strCell;

		if((vDayCount%7==0)&&(j<Cal.GetDaysInMonth()))
		{
			vCalData=vCalData+"</tr>\n<tr>";
		}
	}
	docCal.writeln(vCalData);	
	docCal.writeln("\n</table>");
	docCal.writeln("</form></body></html>");
	docCal.close();
}


/*---------------------------------*/
function GenCell(pValue,pHighLight,pColor)//Generate table cell with value
{
	var PValue;
	var PCellStr;
	var vColor;
	var vHLstr1;//HighLight string
	var vHlstr2;
	
	if (pValue==null)
		PValue="";
	else
		PValue=pValue;
	
	if (pColor!=null)
		vColor="bgcolor=\""+pColor+"\"";
	else
		vColor="";	
	if ((pHighLight!=null)&&(pHighLight))
		{vHLstr1="color='red'><b>";vHLstr2="</b>";}
	else
		{vHLstr1=">";vHLstr2="";}	
	

	PCellStr="<td style='border:black solid 1px;' "+vColor+" width="+CellWidth 
			+ " align='center'><font face='verdana' size='2'"
			+ vHLstr1+"<a href=\"javascript:winMain.document.getElementById('"
			+ Cal.Ctrl+"').value='"
			+ Cal.FormatDate(PValue)+ "'; window.close();\">"
			+ PValue+"</a>"+vHLstr2+"</font></td>";
	return PCellStr;
}


/*---------------------------------*/
function Calendar(pDate,pCtrl)
{
	//Properties
	this.Date=pDate.getDate();//selected date
	this.Month=pDate.getMonth();//selected month number
	this.Year=pDate.getFullYear();//selected year in 4 digits
		
	this.MyWindow=winCal;
	this.Ctrl=pCtrl;
	this.Format="MM-DD-YY";
	this.Separator=DateSeparator;
}


/*---------------------------------*/
function GetMonthIndex(shortMonthName)
{
	for (i=0;i<12;i++)
	{
		if (MonthName[i].substring(0,3).toUpperCase()==shortMonthName.toUpperCase())
		{	return i;}
	}
}
Calendar.prototype.GetMonthIndex=GetMonthIndex;


/*---------------------------------*/
function SwitchYr(index){
	var intYr = 1960 + index;
	Cal.Year=intYr;
	//window.status = "SwitchYr:" + Cal.Year;
}
Calendar.prototype.SwitchYr=SwitchYr;

	
/*---------------------------------*/
function SwitchMth(index){
	Cal.Month=index;
	//window.status = "SwitchMth:" + Cal.Month;
}
Calendar.prototype.SwitchMth=SwitchMth;


/*---------------------------------*/
function GetMonthName(IsLong)
{
	var Month=MonthName[this.Month];
	if (IsLong)
		return Month;
	else
		return Month.substr(0,3);
}
Calendar.prototype.GetMonthName=GetMonthName;


/*---------------------------------*/
function GetDaysInMonth()//Get number of days in a month
{
	var DaysInMonth=[31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
	if (this.IsLeapYear())
	{
		DaysInMonth[1]=29;
	}	
	return DaysInMonth[this.Month];	
}
Calendar.prototype.GetDaysInMonth=GetDaysInMonth;


/*---------------------------------*/
function IsLeapYear()
{
	if ((this.Year%4)==0){
		if ((this.Year%100==0) && (this.Year%400)!=0){
			return false;
		}
		else{
			return true;
		}
	}
	else{
		return false;
	}
}
Calendar.prototype.IsLeapYear=IsLeapYear;


/*---------------------------------*/
function FormatDD(pDate){
	var day = "" + pDate;
	if( day<10){
		day = "0" + day;
	}
	return day;
}
Calendar.prototype.FormatDD = FormatDD;


/*---------------------------------*/
function FormatMM(format){
	var month = (this.Month+1);
	if( month < 10){
		month = "0" + month;
	}
	return month;
}
Calendar.prototype.FormatMM = FormatMM;


/*---------------------------------*/
function FormatYY(format){
	var year;
	if (format.toUpperCase()=="YYYY"){
		year = parseInt(this.Year);
		//alert("YYYY:" + year);
	}
	else if (format.toUpperCase()=="YY"){
		year = parseInt(this.Year) - 1900;
		if(year>100) 
			year = year - 100;
		
		if(year< 10){
			year = "0" + year; 
		}
		//alert("YY:" + year);
	}
	return year;
}
Calendar.prototype.FormatYY = FormatYY;


/*---------------------------------*/
function FormatDate(pDate)
{
	var result;

	if (this.Format.toUpperCase()=="DDMMYYYY")
		result =  (pDate+DateSeparator+(this.Month+1)+DateSeparator+this.Year);
	else if (this.Format.toUpperCase()=="DDMMMYYYY")
		result =  (pDate+DateSeparator+this.GetMonthName(false)+DateSeparator+this.Year);
	else if (this.Format.toUpperCase()=="MMDDYYYY")
		result =  ((this.Month+1)+DateSeparator+pDate+DateSeparator+this.Year);
	else if (this.Format.toUpperCase()=="MMMDDYYYY")
		result =  (this.GetMonthName(false)+DateSeparator+pDate+DateSeparator+this.Year);
	else if (this.Format.toUpperCase()=="MM-DD-YY"){
		result = this.FormatMM("MM")
				+ DateSeparator
				+ this.FormatDD(pDate)
				+ DateSeparator
				+ this.FormatYY("YY");
	}
	return result;
}
Calendar.prototype.FormatDate=FormatDate;