// overly simplistic test for IE
isIE = (document.all ? true : false);
// both IE5 and NS6 are DOM-compliant
isDOM = (document.getElementById ? true : false);

// get the true offset of anything on NS4, IE4/5 & NS6, even if it's in a table!
function getAbsX(elt) { return (elt.x) ? elt.x : getAbsPos(elt,"Left"); }
function getAbsY(elt) { return (elt.y) ? elt.y : getAbsPos(elt,"Top"); }
function getAbsPos(elt,which) {
 iPos = 0;
 while (elt != null) {
  iPos += elt["offset" + which];
  elt = elt.offsetParent;
 }
 return iPos;
}

function getDivStyle(divname) {
 var style;
 if (isDOM) { style = document.getElementById(divname).style; }
 else { style = isIE ? document.all[divname].style
                     : document.layers[divname]; } // NS4
 return style;
}

function hideElement(divname) {
 getDivStyle(divname).visibility = 'hidden';
}

// annoying detail: IE and NS6 store elt.top and elt.left as strings.
function moveBy(elt,deltaX,deltaY) {
 elt.left = parseInt(elt.left) + deltaX;
 elt.top = parseInt(elt.top) + deltaY;
}

function toggleVisible(divname) {
 divstyle = getDivStyle(divname);
 if (divstyle.visibility == 'visible' || divstyle.visibility == 'show') {
   divstyle.visibility = 'hidden';
 } else {
   fixPosition(divname);
   divstyle.visibility = 'visible';
 }
}

function setPosition(elt,positionername,isPlacedUnder) {
 var positioner;
 if (isIE) {
  positioner = document.all[positionername];
 } else {
  if (isDOM) {
    positioner = document.getElementById(positionername);
  } else {
    // not IE, not DOM (probably NS4)
    // if the positioner is inside a netscape4 layer this will *not* find it.
    // I should write a finder function which will recurse through all layers
    // until it finds the named image...
    positioner = document.images[positionername];
  }
 }
 elt.left = getAbsX(positioner);
 elt.top = getAbsY(positioner) + (isPlacedUnder ? positioner.height : 0);
}
         // how reliable is this test?
         isIE = (document.all ? true : false);
	 isDOM = (document.getElementById ? true : false);

         // Initialize arrays.
         var months = new Array("Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul",
	 "Aug", "Sep", "Oct", "Nov", "Dec");
         var daysInMonth = new Array(31, 28, 31, 30, 31, 30, 31, 31,
            30, 31, 30, 31);
	 var displayMonth = new Date().getMonth();
	 var displayYear = new Date().getFullYear();
	 var displayDivName;
	 var displayElement;
	 var globalDay;
	 var globalMonth;
	 var imageBase;

         function getDays(month, year) {
            // Test for leap year when February is selected.
            if (1 == month)
               return ((0 == year % 4) && (0 != (year % 100))) ||
                  (0 == year % 400) ? 29 : 28;
            else
               return daysInMonth[month];
         }

         function getToday() {
            // Generate today's date.
            this.now = new Date();
            this.year = this.now.getFullYear();
            this.month = this.now.getMonth();
            this.day = this.now.getDate();
         }

         // Start with a calendar for today.
         today = new getToday();

         function newCalendar(eltName,attachedElement) {
	    if (attachedElement) {
	       if (displayDivName && displayDivName != eltName) hideElement(displayDivName);
	       displayElement = attachedElement;
	    }
	    displayDivName = eltName;
            today = new getToday();
            var parseYear = parseInt(displayYear + '');
            var newCal = new Date(parseYear,displayMonth,1);
            var day = -1;
            var startDayOfWeek = newCal.getDay();
            if ((today.year == newCal.getFullYear()) &&
                  (today.month == newCal.getMonth()))
	    {
               day = today.day;
            }
            var intDaysInMonth =
               getDays(newCal.getMonth(), newCal.getFullYear());
            var daysGrid = makeDaysGrid(startDayOfWeek,day,intDaysInMonth,newCal,eltName)
	    if (isIE) {
	       var elt = document.all[eltName];
	       elt.innerHTML = daysGrid;
            } else if (isDOM) {
	       var elt = document.getElementById(eltName);
	       elt.innerHTML = daysGrid;
	    } else {
	       var elt = document.layers[eltName].document;
	       elt.open();
	       elt.write(daysGrid);
	       elt.close();
	    }
	 }

	 function incMonth(delta,eltName) {
	   displayMonth += delta;
	   if (displayMonth >= 12) {
	     displayMonth = 0;
	     incYear(1,eltName);
	   } else if (displayMonth <= -1) {
	     displayMonth = 11;
	     incYear(-1,eltName);
	   } else {
	     newCalendar(eltName);
	   }
	 }

	 function incYear(delta,eltName) {
	   displayYear = parseInt(displayYear + '') + delta;
	   newCalendar(eltName);
	 }
	 
	 function setImageBase(img)
	 {	imageBase = img;
	 }

	 function makeDaysGrid(startDay,day,intDaysInMonth,newCal,eltName) {
	    var daysGrid;
	    var month = newCal.getMonth();
	    var year = newCal.getFullYear();
	    var isThisYear = (year == new Date().getFullYear());
	    var isThisMonth = (day > -1)
	    daysGrid = '<table border="1" cellspacing=0 cellpadding=2><tr><td bgcolor="#ddeeee" nowrap>';
	    daysGrid += '<font face="courier new, courier" size=2>';
	    daysGrid += '&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;';
	    daysGrid += '<a href="javascript:incMonth(-1,\'' + eltName + '\')"><img src="' + imageBase + 'calcleft.gif" border="0"/></a>';

	    daysGrid += '<b>';
	    if (isThisMonth) { daysGrid += '<font color=red>' + months[month] + '</font>'; }
	    else { daysGrid += months[month]; }
	    daysGrid += '</b>&nbsp;';
		daysGrid += '<b>';
	    if (isThisYear) { daysGrid += '<font color=red>' + year + '</font>'; }
	    else { daysGrid += ''+year; }
	    daysGrid += '</b>';
	    daysGrid += '<a href="javascript:incMonth(1,\'' + eltName + '\')"><img src="' + imageBase + 'calcright.gif" border="0"/></a>';
	    daysGrid += '&nbsp;&nbsp;&nbsp;';
	   
	    daysGrid += '<br>';
	    daysGrid += '&nbsp;Su Mo Tu We Th Fr Sa&nbsp;<br>&nbsp;';
	    var dayOfMonthOfFirstSunday = (7 - startDay + 1);
	    for (var intWeek = 0; intWeek < 6; intWeek++) {
	       var dayOfMonth;
	       for (var intDay = 0; intDay < 7; intDay++) {
	         dayOfMonth = (intWeek * 7) + intDay + dayOfMonthOfFirstSunday - 7;
		 if (dayOfMonth <= 0) {
	           daysGrid += "&nbsp;&nbsp; ";
		 } else if (dayOfMonth <= intDaysInMonth) {
		   var color = "blue", bgcolorN = "#ddeeee", fontW = "normal";
		   if (day > 0 && day == dayOfMonth) 
		   {	color="black";
		   		bgcolorN = "lightgrey";
		   } else if (dayOfMonth == globalDay && month == globalMonth)
		   {	color="red";
		   		fontW = "bold";
		   }
		   daysGrid += '<a id="monthLink" ';
		   daysGrid += 'onMouseOver="this.style.color=\'red\';" ';
		   daysGrid += 'onmouseout="this.style.color=\'blue\';" ';
		   daysGrid += 'href="javascript:setDay(' + month + ', ';
		   daysGrid += dayOfMonth + ',\'' + eltName + '\')" '
		   daysGrid += 'style="font-weight: ' + fontW + '; font-family: Verdana; font-size: 10pt; text-decoration: none; background-color: ' + bgcolorN + '; color:' + color + '">';
		   var dayString = dayOfMonth + "</a> ";
		   if (dayString.length == 6) dayString = '0' + dayString;
		   daysGrid += dayString;
		 }
	       }
	       if (dayOfMonth < intDaysInMonth) daysGrid += "<br>&nbsp;";
	    }
	    daysGrid += "</td></tr><tr><td bgcolor=#ddeeee nowrap align='center'>";
	    daysGrid += "<a href=\"javascript:hideElement('" + eltName + "');\">Close</a></td></tr>";
	    return daysGrid + "</table>";
	 }

	 function setDay(month, day,eltName) 
	 {
	 	globalMonth = month;
	 	globalDay = day;
	    displayElement.value = displayYear + "-" + (displayMonth + 1) + "-" + day;
	   	hideElement(eltName);
	 }
	 
	function fixPosition(divname) {
	 divstyle = getDivStyle(divname);
	 positionerImgName = divname + 'Pos';
	 // hint: try setting isPlacedUnder to false
	 isPlacedUnder = false;
	 if (isPlacedUnder) {
	  setPosition(divstyle,positionerImgName,true);
	 } else {
	  setPosition(divstyle,positionerImgName)
	 }
	}
	
	function toggleDatePicker(eltName,formElt) {
	  var x = formElt.indexOf('.');
	  var formName = formElt.substring(0,x);
	  var formEltName = formElt.substring(x+1);
	  newCalendar(eltName,document.forms[formName].elements[formEltName]);
	  toggleVisible(eltName);
	}