detect highlighted text

Hi

What I want to do is detect whenever a some text is highlighted/selected in any window

..is there a highlighted event?

I could try to detect mouse drag event perhaps? But it would be better to be able to detect generically when something is highlighted/selected.  

. One solution is to backup the clipboard contents and then do a copy
and if the clipboard is not empty then you know if something is highlighted/selected. But
this requires polling etc.

I have tried detecting mouse up events , but when a mouse up event happens -on a menu  the ^C (copy) - the system beeps.

Is there a is selected /highlighted event..in windows /autoit?

mike