在Applescript中，如何确定菜单项是否被选中/聚焦？

I have a script for OS X 10.5 that focuses the Search box in the Help menu of any application. I have it on a key combination and, much like Spotlight, I want it to toggle when I run the script. So, I want to detect if the search box is already focused for typing, and if so, type Esc instead of clicking the Help menu.I have a script for OS X 10.5 that focuses the