function loadjscssfile(filename, filetype){
 if (filetype=="js"){ //if filename is a external JavaScript file
  var fileref=document.createElement('script')
  fileref.setAttribute("type","text/javascript")
  fileref.setAttribute("src", filename)
 }
 else if (filetype=="css"){ //if filename is an external CSS file
  var fileref=document.createElement("link")
  fileref.setAttribute("rel", "stylesheet")
  fileref.setAttribute("type", "text/css")
  fileref.setAttribute("href", filename)
 }
 if (typeof fileref!="undefined")
  document.getElementsByTagName("head")[0].appendChild(fileref)
}


function isDate(dateStr) {
	var datePat = /^(\d{1,2})(\/|-)(\d{1,2})(\/|-)(\d{4})$/;
	var matchArray = dateStr.match(datePat); // is the format ok?
	
	if (matchArray == null) {
	return false;
	}
	
	day = matchArray[1]; // p@rse date into variables
	month = matchArray[3];
	year = matchArray[5];
	
	if (month < 1 || month > 12) { // check month range
	return false;
	}
	
	if (day < 1 || day > 31) {
	return false;
	}
	
	if ((month==4 || month==6 || month==9 || month==11) && day==31) {
	return false;
	}
	
	if (month == 2) { // check for february 29th
	var isleap = (year % 4 == 0 && (year % 100 != 0 || year % 400 == 0));
	if (day > 29 || (day==29 && !isleap)) {
	return false;
	}
	}
	return true; // date is valid
}