//

// JavaScript Event Calendar

//

// Version: 1.0
// Date: November 15, 1998

// For information: http://members.aol.com/kevinilsen  or kilsen@m-vation.com

//


// Configurable values are set to defaults here; can override them before calling Calendar( ) from the HTML page


var SpecialDay=1;	// 1=Sunday, 2=Monday, . . . 7=Saturday

var FontSize=5;

var ColorBackground="FFFFCC";

var ColorSpecialDay = "red";

var ColorToday = "green";

var ColorEvent = "blue";



// Initialize the range of the calendar to Jan - Dec of the current year.  Calls to DefineEvent( ) will change this

// as needed; it is also possible to explicitly override the range before calling Calendar( ) from the HTML page.



var today = new Date();

var FirstMonth=GetFullYear(today) * 100 + 1;

var LastMonth=FirstMonth + 11;



// Events[] is a SPARSE array; Call DefineEvent( ) to populate it

var Events = new Array;



// Each event is defined by calling the DefineEvent( ) routine with the following parameters:

//

//   DefineEvent(EventDate, EventDescription, EventLink, Image, Width, Height)

//        EventDate is a numeric value in the format YYYYMMDD

//        EvenDescription is a string that can include embedded HTML tags (e.g., <BR>, <strong>, etc.)

//        EventLink is the URL of the target page if a hyperlink is desired from this event entry

//        Image is the URL of the image if you want to display an image with this event

//        Width is the width of the image in pixels

//        Height is the height of the image in pixels



function DefineEvent(EventDate, EventDescription, EventLink, Image, Width, Height) {

	var tmp;



	// Build the HTML string for this event: image (optional), link (optional), and description

	tmp = "";

	if (Image != "")

		tmp = tmp + '<img src="' + Image + '"  width="' + Width + '" height="' + Height + '" align="left" valign="top">';

	if (EventLink != "")

		tmp = tmp + '<a href="' + EventLink + '">';

	tmp = tmp + EventDescription;

	if (EventLink != "") tmp = tmp + '</a>';


	// If an event already exists for this date, append the new event to it.

	if (Events[EventDate])

		Events[EventDate] += "<BR>" + tmp;

	else

		Events[EventDate] = tmp;


	// Adjust the minimum and maximum month & year to include this date

	tmp = Math.floor(EventDate / 100);

	if (tmp < FirstMonth) FirstMonth = tmp;

	if (tmp > LastMonth) LastMonth = tmp;
}




// Utility function to populate an array with values

function arr() {
	for (var n=0;n<arr.arguments.length;n++) {

		this[n+1] = arr.arguments[n];

	}

}


// Create the array of month names (used in various places)

var months = new arr("January","February","March","April","May","June","July","August","September","October","November","December");




// Calendar( ) is the only routine that needs to be called to display the calendar



function Calendar( ) {

	var curdy, curmo, yr, mo, dy, dayofweek, yearmonth, bgn, lastday, jump;

	var weekdays = new arr("Sun","Mon","Tue","Wed","Thu","Fri","Sat");

	var thispage = window.location.pathname;



	// Save current day and month for comparison

	curdy = today.getDate();

	curmo = today.getMonth()+1;



	// Default to current month and year

	mo = curmo;

	yr = GetFullYear(today);

	yearmonth = (yr * 100) + mo;



	// If querystring parameter is present, get the month/year ("calendar.htm?YYYYMM")

	if (location.search.length > 1) {

		yearmonth = parseInt(location.search.substring(1,location.search.length));

		if ((""+yearmonth).length == 6) {

			mo = yearmonth % 100;

			yr = (yearmonth - mo) / 100;

		}

	}




	// Constrain to the range of months with events

	if (yearmonth < FirstMonth) {

		mo = FirstMonth % 100;

		yr = (FirstMonth - mo) / 100;

		yearmonth = FirstMonth;

	}

	if (yearmonth > LastMonth) {

		mo = LastMonth % 100;

		yr = (LastMonth - mo) / 100;

		yearmonth = LastMonth;

	}



	// Create a datae object for the first day of the desired month

	bgn = new Date(months[mo] + " 1," + yr);

	// Get the day-of-week of the first day, and the # days in the month

	dayofweek = bgn.getDay();

	lastday = NumDaysIn(mo,yr);

	document.write("<TABLE BORDER=2 BGCOLOR="+ColorBackground+"><TR><TD ALIGN=CENTER COLSPAN=7><FONT SIZE="+FontSize+"><B>"+months[mo]+" "+yr+"</B></FONT></TD></TR><TR>");

	for (var i=1;i<=7;i++){

		document.write("<TD ALIGN=CENTER WIDTH=14%><FONT SIZE=1>"+weekdays[i]+"</FONT></TD>");

	}

	document.write("</TR><TR>");

	dy = 1;

	// Special handling for the first week of the month

	for (var i=1;i<=7;i++) {

		// If the day is less than the day of the

		// week determined to be the first day

		// of the month, print a space in

		// this cell of the table.

		if (i <= dayofweek){

			document.write("<TD ALIGN=CENTER><FONT SIZE="+FontSize+">&nbsp;</FONT></TD>");

		}

		// Otherwise, write date and the event,

		// if any, in this cell of the table.

		else {

			ShowDate(yr,mo,dy,i,curmo,curdy);

			dy++;

		}

	}

	document.write("</TR><TR>");

	// Rest of the weeks . . .

	while (dy <= lastday) {

		for (var i=1;i<=7;i++) {

			// If the day is greater than the last

			// day of the month, print a space in

			// this cell of the table.

			if (dy > lastday) {

				document.write("<TD ALIGN=CENTER>&nbsp;</TD>");

			}

			// Otherwise, write date and the event,

			// if any, in this cell of the table.

			else {

				ShowDate(yr,mo,dy,i,curmo,curdy);

				dy++;

			}

		}

		document.write("</TR><TR>");

	}


	jump = "";

	if (yearmonth > FirstMonth)

		jump += '<a href="' + thispage + '?'+PrevYearMonth(yearmonth)+'">&lt;-- View '+months[PrevMonth(mo)]+'</a>';

	if ((yearmonth > FirstMonth) && (yearmonth < LastMonth))

		jump += " &nbsp; | &nbsp; ";

	if (yearmonth < LastMonth)

		jump += '<a href="' + thispage + '?'+NextYearMonth(yearmonth)+'">View '+months[NextMonth(mo)]+' --&gt;</a>';

	document.write("</TR><TR><TD colspan=7 align=center>"+jump+"</TD></TR>");

	document.write("<TR><TD colspan=7 align=center valign=middle><FORM>Jump to month:&nbsp;&nbsp;");

	BuildSelectionList(yearmonth, thispage);

	document.write("</FORM></TD></TR></TABLE>");

}




// Display a date in the appropriate color, with events (if there are any)



function ShowDate(yr, mo, dy, dayofweek, currentmonth, currentday) {

	var ind, HighlightEvent, tmp;



	document.write("<TD ALIGN=CENTER VALIGN=TOP><P ALIGN=RIGHT><FONT SIZE="+FontSize);

	HighlightEvent = true;

	if (dayofweek == SpecialDay) {

		document.write(" COLOR=" + ColorSpecialDay);

		HighlightEvent = false;

	}

	if ((mo == currentmonth) && (dy == currentday)) {

		document.write(" COLOR=" + ColorToday);

		HighlightEvent = false;

	}

	ind = (((yr * 100) + mo) * 100) + dy;

	if (Events[ind]) {

		tmp = Events[ind];

		if (HighlightEvent) {

			 document.write(" COLOR=" + ColorEvent);

		}

	} else tmp="&nbsp;<BR>&nbsp;";

	document.write("><B>"+dy+"</B></ALIGN></FONT></P><FONT SIZE=1>"+tmp+"</TD>");

}





// Remaining routines are utilities used above



function NumDaysIn(mo,yr) {

	if (mo==4 || mo==6 || mo==9 || mo==11) return 30;

	else if ((mo==2) && LeapYear(yr)) return 29;

	else if (mo==2) return 28;

	else return 31;


}




function LeapYear(yr) {

	if (((yr % 4 == 0) && yr % 100 != 0) || yr % 400 == 0) return true;

	else return false;

}



// fixes a Netscape 2 and 3 bug
function GetFullYear(d) { // d is a date object

	var yr;


	yr = d.getYear();

	if (yr < 1000)
	yr +=1900;

	return yr;
}

function PrevMonth(mth) {

	if (mth == 1) return 12;

	else return (mth-1);

}



function NextMonth(mth) {

	if (mth == 12) return 1;

	else return (mth+1);


}

function PrevYearMonth(yrmth) {

	if ((yrmth % 100) == 1) return ((yrmth-100)+11);

	else return (yrmth-1);


}

function NextYearMonth(yrmth) {

	if ((yrmth % 100) == 12) return ((yrmth-11)+100);

	else return (yrmth+1);

}



function JumpTo(calendar, thispage) {

	var sel, yrmo;



	sel = calendar.selectedIndex;

	yrmo = calendar.form.jumpmonth[sel].value;

	document.location = thispage + "?" + yrmo;


}

function BuildSelectionList(current,thispage) {

	var mo, yr, yearmonth;


	yearmonth = FirstMonth;

	document.write("<select name=\"jumpmonth\" size=1 onchange=\"JumpTo(this,'" + thispage + "')\">");

	while (yearmonth <= LastMonth) {

		mo = yearmonth % 100;

		yr = (yearmonth - mo) / 100;

		document.write("<option value=");

		document.write(yearmonth);

		if (yearmonth == current) document.write(" selected");

		document.write(">");

		document.write(months[mo]+" "+yr);

		yearmonth = NextYearMonth(yearmonth);

	}

	document.write("</select>");

}