function valContactus(form) {
    if (is_empty(form.name, "Please enter your name")) return false;
    if (is_empty(form.email, "Please enter your email")) return false;
    if (!valid_email(form.email.value)) {
        alert('Please enter a valid email address');
		form.email.focus();
		return false;
	}
    if (is_empty(form.comments, "Please enter comments")) return false;
}

function valRefer(form) {
    if (is_empty(form.name, "Please enter your name")) return false;
    if (is_empty(form.email, "Please enter your email")) return false;
    if (!valid_email(form.email.value)) {
        alert('Please enter a valid email address');
		form.email.focus();
		return false;
	}
}

function is_empty(field, text) {
    if (field.value=="" || !field.value) {
		alert("Please enter " + text);
		field.focus();
		return true;
	} else {
		return false;
	}
}

function valid_email(email) {
    re = /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/
	if (re.test(email)) {
		return true;
	} else {
		return false;
	}
}