function validate() {
    var f = document.forms[1];
    var name=2, email=2, subject=2, query=2;
    var txt = {
        name: 'Your name',
        subject: 'The subject',
        email: 'Your email address',
        query: 'Your comment'
    };

    var required = [];
    for (var i=0; i < f.elements.length; i++)
    {
        var e = f.elements[i];
        switch (e.name)
        {
            case 'name':
            case 'query':
                if (!e.value)
                    required.push(e.name);
                break;
        }
    }
    if (required.length)
    { 
        var msg = "Please supply the following information:\n";
        for (e in required)
            msg += '\n - ' + txt[required[e]];
        alert (msg);
        return false;
    } 
    return true;
}