Creating a menu

hi, i was wondering if anyone could help me create a menu like the one found at [link] . im sure i could find a basic tutorial somewhere on how to make the bar follow the mouse, but getting it to grow depending on the length of the word and then having it extend such as it does on the photos link seems kinda hard o.O. i figured actionscripting would be the way to go. if anyone can help in any way, it would be much appreciated.

thank you