f = document.getElementsByTagName("form");

function verify(x) {
         message = "";
         pattern = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
         e = f[0].elements;
         if (e[1].value=="") {message += "First Name is required\n";}
         if (e[2].value=="") {message += "Surname is required\n";}
         if (e[9].value=="") {message += "Email address is required\n";}
            else if (!pattern.test(e[9].value)) {message += "Email address invalid\n";}
	 if (e[11].value.length>500) {message += "Message must not exceed 500 characters";}
         if (message!="") {alert(message);return false;}
            else {return true;}
}