jQuery form ajaxSubmit not getting triggered

Question

I got a weird problem with ajaxSubmitting a form. My function gets triggered, but the ajaxSubmit itself does not get triggered.

Here is my HTML:

<div id='respond_4'></div>
<form method='post' id='cropper_4_infoForm' action=''>
    <input type='text' name='imag_title' value='' />
    <input type='hidden' name='image_filename' id='image_4_filename' value='' />
    <input type='hidden' name='image_x' id='image_4_x' />
    <input type='hidden' name='image_y' id='image_4_y' />
    <input type='hidden' name='image_width' id='image_4_width' />
    <input type='hidden' name='image_height' id='image_4_height' />
    <input type='hidden' name='image_rotate' id='image_4_rotate' />
</form>

<button type='button' class='btn' onclick='SaveCropImageInfo();'><div class='icon icon-save'></div> Opslaan</button>

Here is my JavaScript:

function SaveCropImageInfo() {
        console.log('going');
        $('#cropper_4_infoForm').ajaxSubmit({ 
            target:     '#respond_4', 
            url:        '/cms/modules/website/include/ajax/saveCropImageInfo.php?imag_id=4'
        });
    }

I have another form on this page that works on the same principal, but with different target and different url, but that form does work as intended. Hope one of you guys can help me out. :)