//these are the default values when form is reset
var firstyear=1990;

//all array with spaces
var all = new Array("-   ");

//this function will set the right # of days in the dropdown
//depending on what month is passed in.
function swapOptions(month, daydropdown, yeardropdown)
{
	//var numbers_select = window.document.mainform.days;
	var MonthOption=31; 
	var mystr = month.toLowerCase();
    //if month changes, change year as well
    swapYear(yeardropdown)
	if (mystr=="february" ){
      MonthOption = 28;
      if(isLeapYear(yeardropdown)=="true") MonthOption = 29;
    }
	if (mystr=="april" || mystr=="june" || mystr=="september" || mystr=="november") MonthOption = 30;
        //options depend on whether "all" was chosen or not
    if (mystr!="all" && mystr!='choose') {
    	var montharray = new Array(MonthOption);
            //spaces to set formatting on page
        var tempstr="";
        for (loop =1; loop <=MonthOption; loop++){
            tempstr = loop.toString();
            if (loop < 10) tempstr="0"+tempstr;
            montharray[loop-1]=tempstr;
        }
    	setOptionText(daydropdown, montharray);   
        swapYear(yeardropdown)
    }
    else {
      setOptionText(daydropdown, all);   
      setOptionText(yeardropdown, all);
      yeardropdown.selectedIndex = 0;
    }


}

//MUST have leapyear functionality, otherwise it breaks
function isLeapYear(yeardropdown){
    var yearint = eval(yeardropdown.value);
    var isLeap="false";
    //if a year is divisible by 4, but NOT 100,it's a leap year
    if (yearint % 4==0 && yearint %100 !=0) isLeap ="true";
    //however, if it's divisible by 400, it IS a leap year
    if (yearint % 400 ==0) isLeap = "true";
    return isLeap;
}

//this function will only be called at most once per year dropdown
function swapYear(yeardropdown)
{
  if (yeardropdown.options.length<2){
      var d =new Date();
      var curryear = d.getFullYear(); //year depends on CLIENT machine
      var yeararray = new Array();
         //years from present back to firstyear will be shown
      for (loop =curryear; loop >= firstyear; loop--){
         yeararray.push(loop);
      }
      setOptionText(yeardropdown, yeararray);
   }
}

//called internally to set the text
//note the box needs to be resized.
function setOptionText(the_select, the_array)
{
    var currselect = the_select.options.selectedIndex;
    the_select.options.length=the_array.length;
	for (loop=0; loop < the_select.options.length; loop++)
	{
		the_select.options[loop] = new Option(the_array[loop], the_array[loop]);
	}
    if (currselect < the_array.length)
        the_select.options.selectedIndex = currselect;
    else
        the_select.options.selectedIndex = the_array.length - 1;
}

function initDates(){
  var myfrm = document.forms[0];
//reset all drop downs
  setOptionText(myfrm.myday, all);   
  setOptionText(myfrm.myyear, all);
  myfrm.myyear.options.selectedIndex = 0;
  myfrm.mymonth.options.selectedIndex = 0;
  myfrm.myday.options.selectedIndex = 0;
}

function initStartEndDates(){
  var myfrm = document.forms[0];
//reset all drop downs
  setOptionText(myfrm.mydaystart, all);   
  setOptionText(myfrm.myyearstart, all);
  myfrm.myyearstart.options.selectedIndex = 0;
  myfrm.mymonthstart.options.selectedIndex = 0;
  myfrm.mydaystart.options.selectedIndex = 0;
  setOptionText(myfrm.mydayend, all);   
  setOptionText(myfrm.myyearend, all);
  myfrm.myyearend.options.selectedIndex = 0;
  myfrm.mymonthend.options.selectedIndex = 0;
  myfrm.mydayend.options.selectedIndex = 0;

}