function openWindow(sURL,sWindowName,w,h) {
	oWin = window.open(sURL, sWindowName, 'toolbar=0, location=0, directories=0, status=0, menubar=no, scrollbars=yes, resizable=yes, width='+w+', height='+h);
	oWin.focus();
}

function validate(field) {
	var entry = field.value;
	if (!jly_validate_postcode(entry)) {
		alert("Invalid entry! Please enter a valid postcode.");
		field.focus();
		field.select();
		return false;
	}
}

function  jly_validate_postcode( vsString ) {
	var loRegExp  =  /(\d\d\d\d$)/;
	return loRegExp.test(vsString);
}