/*
Client side scripts required to support the date selection dropdowns
Author: Michael McLain
Note: These scripts must be placed prior to calling the GenDateDropDown subroutine
Return number of days in a month
Parameters: lnMonth: month (1-12)
            lnYear:  year => 1970
*/
var initflag=false	//Patch for date textbox example
function daysinmonth(lnMonth,lnYear) {
var dt1, cmn1, cmn2, dtt, lflag, dycnt, lmn
lmn = lnMonth-1
dt1 = new Date(lnYear,lmn,1)
cmn1 = dt1.getMonth()
dtt=dt1.getTime()+2332800000
lflag = true
dycnt=28
while (lflag) {
   dtt = dtt + 86400000
   dt1.setTime(dtt)
   cmn2 = dt1.getMonth()
   if (cmn1!=cmn2) {
      lflag = false }
   else {dycnt = dycnt + 1}}
if (dycnt > 31) {dycnt = 31}
return dycnt
}

function setdays(sobjname, datemode){
	if(document.forms[0]){
		var dobj = eval(sobjname + "d")
		var mobj = eval(sobjname + "m")
		var yobj = eval(sobjname + "y")
		var hobj = eval(sobjname)
		var monthdays = daysinmonth(mobj.options[mobj.selectedIndex].value,yobj.options[yobj.selectedIndex].value)
		var selectdays = dobj.length
		var curdy = dobj.options[dobj.selectedIndex].value
		if (curdy.length==1) {curdy = "0"+curdy}
		var curmn = mobj.options[mobj.selectedIndex].value
		if (curmn.length==1) {curmn = "0"+curmn}
		var curyr = yobj.options[yobj.selectedIndex].value
		if (selectdays > monthdays) {
		   for (var dlp=selectdays; dlp > monthdays; dlp--) {
			   dobj.options[dlp-1] = null }}
		else if (monthdays > selectdays) {
		   for (var dlp=selectdays; dlp < monthdays; dlp++) {
			   dobj.options[dlp] = new Option(dlp+1,dlp+1) }}       
		if (curdy > monthdays) {
		   dobj.options[monthdays-1].selected = true
		   curdy = monthdays }
		if (datemode==1) {
		   var curdate = curmn+"/"+curdy+"/"+curyr }
		else if (datemode==2) {
		   var curdate = curdy+"/"+curmn+"/"+curyr }
		else if (datemode==3) {
		   var curdate = curyr+curmn+curdy }
		else if (datemode==4) {
		   var cdate = new Date(curyr,curmn-1,curdy)
		   var curdate = cdate.toGMTString() }
		
		hobj.value = curdate
		//Patch for example date text box
		
		if (sobjname=="document.forms[0].date1" && initflag) {
		   document.wetterarchiv_form.date_txt.value = curdate;
			}
	}
}

initflag=true;