How to avoid form re-submission if browser back button is selected?
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Let's consider a scenario like below :

 1. Symfony2 provides a removal form for an entity
 2. User selects remove button
 3. Symfony2 controller will remove the entity and redirect the User to confirmation page
 4. If user select browser back button he/she will see the record and removal form again
 5. Selecting Remove button will throw an exception because it was removed already 


What is the best way to avoid back button and re-submissions ?   

The controller for this question is the same as [here][1].


  [1]: http://stackoverflow.com/questions/11547090/how-should-a-controller-with-methodpost-handle-the-request-if-submitted-fo