function checkReviewForm( f ) {
    for( var i = 0, n = f.elements.length; i < n; i++ ) {
        var el = f.elements[i];
        if ( el.getAttribute( 'required' ) != null && el.value == '' ) {
            alert( "All fields except URL are required.\nPlease fill out all required fields. Thank you.");
            return false;
        }
    }
    return true;
}