Moving a bounding box to a specific location (dynamically)

programming flash
1

Dear all,

This is my first post on this forum, I have never posted so far but have been reading this website often. I am encountering a very major problem and I will really appreciate any help.

**Issue: I need to move a rectangle (that has only sides and no fills) to a specific location on the animation, what happens is that if the user enters some info (through HTML form processed by PHP and sent to the movie through FlashVars), this info should then help me find the x and y coordinates of a button that should then be overlapped by this said rectangle.
**
Code:

if (_root.signUp == 1){                      // the FlashVar variable flag
var buttoSym= "_root.thumbMain.thumbSymbol.b" + _root.signNumber
/* above - my buttons are named as _root.thumbMain.thumbSymbol.b1, b2 and so on... */
_root.boundBox._x = buttoSym._x - 20
_root.boundBox._y = buttoSum._y - 20
}

But it doesn’t work. when I trace buttoSym or buttoSym._x I get undefined.

I will really appreciate any help in this matter. Many thanks.