function validate() {

var first = document.form1.textfield.value;
var last = document.form1.textfield2.value;
var email = document.form1.textfield3.value;

	if (first == '') {
		alert('Please enter first name.');
		document.form1.textfield.focus();
		return false;
	}
	if (last == '') {
		alert('Please enter last name.');
		document.form1.textfield2.focus();
		return false;
	}
	if (!checkemail(email)  ) {
		alert('Please enter a valid email address.');
		document.form1.textfield3.focus();
		return false;
	}
	
}


function checkemail(str){
	var filter=/^([\w-]+(?:\.[\w-]+)*)@((?:[\w-]+\.)*\w[\w-]{0,66})\.([a-z]{2,6}(?:\.[a-z]{2})?)$/i ;
	if (filter.test(str)) {
		return true;
	 } else{
		return false;
	}
}