[jQuery] Validation

[Jojje]

Hi, i cant figure this one out!!!

I´m using the validation plugin and want to validate a form to a
guestbook. Im using ajax to post the message .
the problem is that when i submit the form the first time it´s fine,
but the second time it posts twice, and the third time it posts three
times, and so on. adding one every time i submit. heres the script:

$(function() {
        $("form#send_gb").validate({
        submitHandler: function(form) {
        $(form).submit(function(e) {
                var gb_post = $("#gb_post").attr("value");
                var userid = $("#userid").attr("value");
                var ownerid = $("#ownerid").attr("value");
                $.ajax({
                        type: "POST",
                        url: "_scripts/send_message.php",
                        data: "action=send_gb& gb_post="+ gb_post +"& userid="+ 
userid +"&
ownerid="+ ownerid,
                        beforeSend: function() {
                               $("#gbPosts").prepend("<div id='sending'><div>");
                       },
                        success: function() {
                                
$("#gbPosts").load("_members/gb_posts.php?funk&userID="+userid,
function(){
                                        
$(".gb_message:first-child").hide().fadeIn(1200);
                                        $("#gb_post").attr("value","");
                                });
                        }
                });
                e.preventDefault();
            });
        }
   });
});

Does anyone see what i´m doing wrong? help would be muuuuch
apreciated.

Thanks in advance

Jojje