function validate(){
	var sRegFields = document.forms[0]._required.value.split(", ");

	for(var i = 0; i < sRegFields.length; i++){
		if(document.forms[0].elements[sRegFields[i]].value == ""){
			alert("'" + sRegFields[i] + "' is required.");
			return false;
		}
	}
	return true;
}
function corner(s){
	var eAll = document.getElementById('corner').getElementsByTagName('SPAN');
	var eNew = document.getElementById(s);
	var sContent = eNew.innerHTML;

	for(var i=0; i < eAll.length; i++){
		eAll[i].style.display = "none";
	}
	eNew.style.display = "block";
}