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="300";//top coordinate of calendar window.
	var cnLeft="100";//left coordinate of calendar window
	var WindowTitle ="DateTime Picker";//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 WeekHeadColor="#0099CC";//Background Color in Week header.
	var SundayColor="#6699FF";//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="#FFFF33";//Background color of today.
	var SelDateColor="#FFFF99";//Backgrond color of selected date in textbox.
	var YrSelColor="#cc0033";//color of font of Year selector.
	var ThemeBg="";//Background image of Calendar window.
	//end Configurable parameters
	//end Global variable

	function NewCal(pCtrl,pFormat,pShowTime,pTimeMode)
	{
		Cal=new Calendar(dtToday);
		if ((pShowTime!=null) && (pShowTime))
		{
			Cal.ShowTime=true;
			if ((pTimeMode!=null) &&((pTimeMode=='12')||(pTimeMode=='24')))
			{
				TimeMode=pTimeMode;
			}		
		}	
		if (pCtrl!=null)
			Cal.Ctrl=pCtrl;
		if (pFormat!=null)
			Cal.Format=pFormat.toUpperCase();
		
		exDateTime=document.getElementById(pCtrl).value;
		if (exDateTime!="")//Parse Date String
		{
			var Sp1;//Index of Date Separator 1
			var Sp2;//Index of Date Separator 2 
			var tSp1;//Index of Time Separator 1
			var tSp1;//Index of Time Separator 2
			var strMonth;
			var strDate;
			var strYear;
			var intMonth;
			var YearPattern;
			var strHour;
			var strMinute;
			var strSecond;
			//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);
			}
			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.GetMonDays()) && (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);
			//end parse year
			//parse time
			if (Cal.ShowTime==true)
			{
				tSp1=exDateTime.indexOf(":",0)
				tSp2=exDateTime.indexOf(":",(parseInt(tSp1)+1));
				strHour=exDateTime.substring(tSp1,(tSp1)-2);
				Cal.SetHour(strHour);
				strMinute=exDateTime.substring(tSp1+1,tSp2);
				Cal.SetMinute(strMinute);
				strSecond=exDateTime.substring(tSp2+1,tSp2+3);
				Cal.SetSecond(strSecond);
			}	
		}
		winCal=window.open("","DateTimePicker","toolbar=0,status=0,menubar=0,fullscreen=no,width=195,height=225,resizable=0,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 background='"+ThemeBg+"' link="+FontColor+" vlink="+FontColor+"><form name='Calendar'>");

		vCalHeader="<table border=1 cellpadding=1 cellspacing=1 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+="</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 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.GetMonDays();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.GetMonDays()))
			{
				vCalData=vCalData+"</tr>\n<tr>";
			}
		}
		docCal.writeln(vCalData);	
		
		//Time picker
		if (Cal.ShowTime)
		{
			var showHour;
			showHour=Cal.getShowHour();		
			vCalTime="<tr>\n<td colspan='7' align='center'>";
			vCalTime+="<input type='text' name='hour' maxlength=2 size=1 style=\"WIDTH: 22px\" value="+showHour+" onchange=\"javascript:winMain.Cal.SetHour(this.value)\">";
			vCalTime+=" : ";
			vCalTime+="<input type='text' name='minute' maxlength=2 size=1 style=\"WIDTH: 22px\" value="+Cal.Minutes+" onchange=\"javascript:winMain.Cal.SetMinute(this.value)\">";
			vCalTime+=" : ";
			vCalTime+="<input type='text' name='second' maxlength=2 size=1 style=\"WIDTH: 22px\" value="+Cal.Seconds+" onchange=\"javascript:winMain.Cal.SetSecond(this.value)\">";
			if (TimeMode==12)
			{
				var SelectAm =(parseInt(Cal.Hours,10)<12)? "Selected":"";
				var SelectPm =(parseInt(Cal.Hours,10)>=12)? "Selected":"";

				vCalTime+="<select name=\"ampm\" onchange=\"javascript:winMain.Cal.SetAmPm(this.options[this.selectedIndex].value);\">";
				vCalTime+="<option "+SelectAm+" value=\"AM\">AM</option>";
				vCalTime+="<option "+SelectPm+" value=\"PM\">PM<option>";
				vCalTime+="</select>";
			}	
			vCalTime+="\n</td>\n</tr>";
			docCal.write(vCalTime);
		}	
		//end time picker
		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;
		var vTimeStr;
		
		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="";}	
		
		if (Cal.ShowTime)
		{
			vTimeStr="winMain.document.getElementById('"+Cal.Ctrl+"').value+=' '+"+"winMain.Cal.getShowHour()"+"+':'+"+"winMain.Cal.Minutes"+"+':'+"+"winMain.Cal.Seconds";
			if (TimeMode==12)
				vTimeStr+="+' '+winMain.Cal.AMorPM";
		}	
		else
			vTimeStr="";		
		PCellStr="<td "+vColor+" width="+CellWidth+" align='center'><font face='verdana' size='2'"+vHLstr1+"<a href=\"javascript:winMain.document.getElementById('"+Cal.Ctrl+"').value='"+Cal.FormatDate(PValue)+"';"+vTimeStr+";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.Hours=pDate.getHours();	
		
		if (pDate.getMinutes()<10)
			this.Minutes="0"+pDate.getMinutes();
		else
			this.Minutes=pDate.getMinutes();
		
		if (pDate.getSeconds()<10)
			this.Seconds="0"+pDate.getSeconds();
		else		
			this.Seconds=pDate.getSeconds();
			
		this.MyWindow=winCal;
		this.Ctrl=pCtrl;
		this.Format="ddMMyyyy";
		this.Separator=DateSeparator;
		this.ShowTime=false;
		if (pDate.getHours()<12)
			this.AMorPM="AM";
		else
			this.AMorPM="PM";	
	}

	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 IncYear()
	{	Cal.Year++;}
	Calendar.prototype.IncYear=IncYear;

	function DecYear()
	{	Cal.Year--;}
	Calendar.prototype.DecYear=DecYear;
		
	function SwitchMth(intMth)
	{	Cal.Month=intMth;}
	Calendar.prototype.SwitchMth=SwitchMth;

	function SetHour(intHour)
	{	
		var MaxHour;
		var MinHour;
		if (TimeMode==24)
		{	MaxHour=23;MinHour=0}
		else if (TimeMode==12)
		{	MaxHour=12;MinHour=1}
		else
			alert("TimeMode can only be 12 or 24");		
		var HourExp=new RegExp("^\\d\\d$");
		if (HourExp.test(intHour) && (parseInt(intHour,10)<=MaxHour) && (parseInt(intHour,10)>=MinHour))
		{	
			if ((TimeMode==12) && (Cal.AMorPM=="PM"))
			{
				if (parseInt(intHour,10)==12)
					Cal.Hours=12;
				else	
					Cal.Hours=parseInt(intHour,10)+12;
			}	
			else if ((TimeMode==12) && (Cal.AMorPM=="AM"))
			{
				if (intHour==12)
					intHour-=12;
				Cal.Hours=parseInt(intHour,10);
			}
			else if (TimeMode==24)
				Cal.Hours=parseInt(intHour,10);	
		}
	}
	Calendar.prototype.SetHour=SetHour;

	function SetMinute(intMin)
	{
		var MinExp=new RegExp("^\\d\\d$");
		if (MinExp.test(intMin) && (intMin<60))
			Cal.Minutes=intMin;
	}
	Calendar.prototype.SetMinute=SetMinute;

	function SetSecond(intSec)
	{	
		var SecExp=new RegExp("^\\d\\d$");
		if (SecExp.test(intSec) && (intSec<60))
			Cal.Seconds=intSec;
	}
	Calendar.prototype.SetSecond=SetSecond;

	function SetAmPm(pvalue)
	{
		this.AMorPM=pvalue;
		if (pvalue=="PM")
		{
			this.Hours=(parseInt(this.Hours,10))+12;
			if (this.Hours==24)
				this.Hours=12;
		}	
		else if (pvalue=="AM")
			this.Hours-=12;	
	}
	Calendar.prototype.SetAmPm=SetAmPm;

	function getShowHour()
	{
		var finalHour;
	    if (TimeMode==12)
	    {
	    	if (parseInt(this.Hours,10)==0)
			{
				this.AMorPM="AM";
				finalHour=parseInt(this.Hours,10)+12;	
			}
			else if (parseInt(this.Hours,10)==12)
			{
				this.AMorPM="PM";
				finalHour=12;
			}		
			else if (this.Hours>12)
			{
				this.AMorPM="PM";
				if ((this.Hours-12)<10)
					finalHour="0"+((parseInt(this.Hours,10))-12);
				else
					finalHour=parseInt(this.Hours,10)-12;	
			}
			else
			{
				this.AMorPM="AM";
				if (this.Hours<10)
					finalHour="0"+parseInt(this.Hours,10);
				else
					finalHour=this.Hours;	
			}
		}
		else if (TimeMode==24)
		{
			if (this.Hours<10)
				finalHour="0"+parseInt(this.Hours,10);
			else	
				finalHour=this.Hours;
		}	
		return finalHour;	
	}				
	Calendar.prototype.getShowHour=getShowHour;		

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

	function GetMonDays()//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.GetMonDays=GetMonDays;

	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 FormatDate(pDate)
	{
		if (this.Format.toUpperCase()=="DDMMYYYY")
			return (pDate+DateSeparator+(this.Month+1)+DateSeparator+this.Year);
		else if (this.Format.toUpperCase()=="DDMMMYYYY")
			return (pDate+DateSeparator+this.GetMonthName(false)+DateSeparator+this.Year);
		else if (this.Format.toUpperCase()=="MMDDYYYY")
			return ((this.Month+1)+DateSeparator+pDate+DateSeparator+this.Year);
		else if (this.Format.toUpperCase()=="MMMDDYYYY")
			return (this.GetMonthName(false)+DateSeparator+pDate+DateSeparator+this.Year);			
	}
	Calendar.prototype.FormatDate=FormatDate;