Im using Dojo to create a simple dialog to create a user in a system. The problem is I get the error:

Tried to register widget with `id==user_submit` but that `id` is already registered

user_submit, is a Dojo button I have to finish the form inside the dialog. When I close the dialog by clicking it and submitting the form there is no problem in opening the dialog again (in the click event on the button I have this line of code:

dijit.byId(user_submit).destroy();

but if I close the dialog through the [x]-link / button in the top-right corner I don't destroy the button and then can't open the dialog again without reloading the page.

How do I get Dojo to destroy the button or how to a overload the click-event on [X]-link / button, so I can write the destroy command for the button?