<!--
function validateThis() {
	if (demo.name.value == '' || demo.name.value == ' ') {
		alert("Please enter your name");
		demo.name.focus();
	} else if (demo.age.value == '' || demo.age.value == ' ' || !isNumber(demo.age)) {
		alert("Please enter your age");
		demo.age.focus();
	} else if (demo.city.value == '' || demo.city.value == ' ') {
		alert("Please enter your city");
		demo.city.focus();
	} else if (demo.email.value == '' || !isEmail(demo.email.value)) {
		alert("Please enter a valid email address");
		demo.email.focus();
	} else {
		demo.submit();
	}
}
function isEmail(string) {
    if (string.search(/^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/) != -1)
        return true;
    else
        return false;
}
function isNumber(string) {
	if (string.value.search(/^[0-9]*$/) != -1) 
		return true;
	else 
		return false;
}
//-->