Passing checkbox state to controller

[MOZ]

I'm trying to mod this addon: http://xenforo.com/community/resources/hdjuegos-net-watermark-add-on.224/

So that when users are attaching an image, they can tick off a checkbox to enable/disable the watermarking.

However I have been unable in passing the value from the template attachment_upload_button to the XenForo_ControllerPublic_Attachment::actionDoUpload controller action.

Any ideas on how to go about this?

 

[MOZ]

Any idea on how to do this?