How to perform cleanup tasks when clicked on "End Job"

System

Hello All,

We have a workflow which have a task which performs some locking task when workflow starts. The unlocking is performed by an external task which is just before endtask.

But when someone ends it manually by clicking "End Job" the unlock task doesn't get executed and no unlocking is done. This results in some inconsistencies.

Any idea how should I tackle this.

Thanks in Advance.