function validategb() {

if (document.sign.name.value=="") {
    alert("Please enter your name.");
    document.sign.name.focus();
    return false;
}


if (document.sign.email.value=="") {
    alert("Please enter your email address.");
    document.sign.email.focus();
    return false;
}

part1 = document.sign.email.value.indexOf("@");
part2 = document.sign.email.value.indexOf(".");
part3 = document.sign.email.value.length;
if (!(part1 >= 3 && part2 >= 6 && part3 >= 9)) {
    alert ("Not a valid e-mail address!");
    document.sign.email.focus();
    return false;
}

if (document.sign.message.value=="") {
    alert("Please enter a message");
    document.sign.message.focus();
    return false;
}

string1 = document.sign.message.value.indexOf("script");
if (!(string1==-1)) {
    alert ("Not a valid message");
    document.sign.message.focus();
    return false;
}


}