How to Close Window Automatically upon Its Deactivation
Available in: Actual Window Manager, Actual Window Guard.
Create specific settings for the desired target window.
Go to the Closing property sheet of just created settings.
In the Close Window Automatically group mark the After deactivation check box.
(Optional) If you don't want your target window closed immediately when it becomes inactive, you can mark the related Delay before closing check box and specify how long to wait before closing.
Example
Typing 7.5 will mean that the target window will be closed seven and half seconds after the moment it's deactivated.Apply your adjustments.