// JavaScript Document
function validate_required(field,alerttxt) {
	with (field) {
		if (value==null||value=="") {
			alert(alerttxt);return false;
		} else {
			return true;
		}
	}
}

function validate_form(thisform) {
	with (thisform) {
		if (validate_required(postcode,"Please enter a London location (e.g Southwark, Tottenham Court Road, or SE1)")==false) {
			postcode.focus();return false;
		}
	}
}