I am using jQuery File Upload plugin (<http://blueimp.github.io/jQuery-File-Upload/>) for image upload for my website.

My Code:

```
$('#fileupload').fileupload({
    url: 'server/index.php',
    dataType: 'json',
    dropZone: $('#dropzone'),
    disableImageResize: false,
    imageMaxWidth: 800,
    imageMaxHeight: 800,
    acceptFileTypes: /(\.|\/)(gif|jpe?g|png)$/i,
    maxNumberOfFiles:3,
    singleFileUploads: false,
});

```

When user try to upload more than 3 files, the script does prevent files from being uploaded. But it doesn't do anything or show anything to tell user that their files is over limit.

So, how can I have the plugin to display an alert box when user try to upload files more than maximum number allowed?

Thank you.