Run menu action in background

["Philipp E. Letschert" <phil uni-koblenz de>]

Hi,

I have a subroutine connected to a popup menu item. When that routine is
finished a new popup window displays the result. Sometimes the routine takes
longer to finish and during that time the popup menu stays visible.

How can I run the subroutine in background and have the popup menu disappear
right after activating the menu item?

Thanks, Phil