// catalog request send function
function sendCatalogRequest () {
    // get catalog request form reference
    var cf = $('#catreq form');

    // get list of required fields
    var required = cf.find('input.required-form-element');

    var invalid = false;

    // validate required fields
    if ( 'object' == typeof required ) {
        var index = 0;

        while( required.hasOwnProperty(index) ) {
            // get input reference
            var input = $(required[index]);

            // remove invalid
            input.removeClass('invalid');

            // validate input lenght
            if ( input.val().length == 0 ) {
                // hilight input
                input.addClass('invalid');

                // remember invalid field
                invalid = true;
            }

            index++;
        }
    }

    // some invalid fields
    if ( true === invalid ) {
        alert('To complete your catalog request please fill in all missing fields.');
        return false;
    }

    // everything filled in, submit form
    // add security code
    cf.append('<input type="hidden" name="sec" value="loremipsum" />').submit();
}