function check_required(){
	var req = document.getElementById('required').value;
	var _req = req.split(",");
	var element;
	var ok;
	
	for(var i = 0; i < _req.length; i++){
		element = document.getElementById(_req[i]);

		if(element.value == ''){	
			alert("Please fill in all required(*) fields.");
			element.focus();
			return false;
		}
	}
	
	return true;
}