Untitled

<html>
<head>
<script>
window.onload = function () {
    function validate() {
        var fname = document.forms["signUp"]["fname"].value;
        var sname = document.forms["signUp"]["sname"].value;

        if(fname == "" || sname == "") {
            return false;
        }
    }
}
</script>
</head>

<body>
    <form name="signUp" action="http://naivist.net/form" method="GET" onsubmit="return validate()">
        <div>
            <label>Name</label>
            <input type="text" name="fname">
            <label>Surname</label>
            <input type="text" name="sname">
        </div>
        <input type="submit">
    </form>
</body>
</html>