Retain a button’s rollover state while rolling over a pop-up menu

TechNote: When the user moves the cursor over a button in a navigation menu in a web browser, the button swaps out the “up” state image and replaces it with the “over” state image. If there is a pop-up menu attached to the button and the user rolls over the pop-up menu, the button with the pop-up menu behavior then swaps back to the “up” state even though the pop-up menu is part of the button’s behaviors.