How to create clickable image in form

I can create a form image object and show an image just fine but how do I make this clickable?
I don’t want to use the file upload functionality of the image, just react to the click event but I can’t see any way to do this.
Another option may be to have an image on a transparent button but I don’t see how to do this either.

Unfortunately there is no “image button” control in the dhtmlxForm.
You may try to create your own custom control in the dhtmlxForm: