Attach this behavior to a sprite that you want to act as a rollover sprite, ie, when the mouse enters this sprite, a window appears, (as long as the mouse is not down on mouseEnter and the window to be opened is instantiated) and when the mouse leaves this sprite, the window disappears. You will be prompted for the name of the window you want to open when you drop this behavior on a sprite.
This behavior will not work right if the window you open is modal.
You can see this used in the demo that comes with WFS in scene 7 if you mouseover the triangle and then menu1>menu1,2. That example shows a relatively improbable use of the "Rollover" behavior: the words "rollover1" and "rollover2" are menu items that open rollover windows. Usually you'd use the "Rollover" behavior not on a menu item but a window element.
Attach this to the sprite you want to open the window on mouseEnter and close the window on mouseLeave.
If you write and attach other behaviors to a sprite to which you've attached the "Rollover" behavior that, for instance, change the image or highlight the text , then the mouseEnter behavior should have the following form to be consistent with the Rollover behavior. This behavior has two mouse events: mouseEnter and mouseLeave. The mouseLeave handler closes the window unconditionally.
When you drag and drop a copy of the "Rollover" behavior on a sprite, the following dialog box opens.
You specify the name of the window you want to open.