[jQuery] From plugin and submit

Hi
When trying out the Form plugin (http://malsup.com/jquery/form/) I have this
$('#myform').submit(function() {
    $(this).ajaxSubmit({
        url: '/some/generated/value',
    });
    return false;
});
Which works fine, except the value of the submit button is not sent to the
server. As I test for this value server side, it is a problem for me. Any easy
way to include/set the submit button?