[jQuery] JQuery Forms plugin, success callback fail

[arkstone]

Hi all!

I have this code:

                $("#loading")
                .ajaxStart(function()
                {
                        $(this).show();
                })
                .ajaxComplete(function()
                {
                        $(this).hide();
                });
                var options =
                {
                        beforeSubmit:   showRequest,
                        success:        showResponse,
                        url:            '/library/scripts/upload.php',
                        clearForm:      true,
                        dataType:       'json'
                };
                $('#ajax_form').submit(function()
                {
                        $(this).ajaxSubmit(options);
                        return false;
                });


function showRequest(formData, jqForm, options)
{
        var fileToUploadValue = $('#upFileInput').val();
        if (fileToUploadValue == "")
        {
                alert('Пожалуйста, выберите файл для загрузки.');
                return false;
        }
        return true;
}

function showResponse(data, statusText)
{
        alert(data);
        cropScreen();
        $('#cropPhoto').html(data);
}


upload.php output is: <img src="imgpath">

But success event won't trigger at all, I've checked and rechecked
all, but can't find the problem source. Apache logs says that
upload.php was called and completed with code 200 (success).

Sadly I cannot give link to see it, cause it's on our internal server
and I'm forbidden to put it on any ext server.