Ajax发送重复的头

Well I have stumbled upon a weird problem.

First time I send the form the server recieves 1. If I send another without reloading the page it sends 2 exact same posts, if I send it again it sends 3 and so on. If I would to send 9 forms it would send 9 exact same posts on the last.

Here's my code:

$('#AskACounsel .btn-ask-question').bind("click", function (e) {
    e.preventDefault();

    var textbox = $('#AskACounselQuestion');
    var question = textbox.val();    
    var product = textbox.data('productid');

    if (question.length > 0) {    
        var params = { question: question, productid: product };    
        var url = '/FAQService/AddQuestion';
        $.ajax({
            url: url, success: function (result) {    
                var infoDiv = $('#AskACounselThankYouView .counsel-info').html(result.Message);
                var backDiv = $('#AskACounselThankYouView .counsel-footer .btn-return');
                if (result.Success) {
                    textbox.val("");
                    backDiv.hide();
                } else {
                    backDiv.show();
                }

                $('#AskACounselDefaultView').hide();
                $('#AskACounselThankYouView').show();
            },
            type: 'POST',
            data: params    
        });
    }    
});