Selecting canvas by using GUI buttons

Hi, I'm trying to use the root GUI to select a canvas and re-draw it. I create two Canvases and then I need to use GUI buttons to bring the selected one in front of the other.

The attached macro works properly on:

• Scientific Linux CERN Release 3.0.5 (SL)
• gcc version 3.2.3 20030502 (Red Hat Linux 3.2.3-53)
• root Version: 5.06/00

The same macro does'n work with:

• Gentoo Base System version 1.12.0_pre10
• gcc version 3.3.6 (Gentoo 3.3.6, ssp-3.3.6-1.0, pie-8.7.8)
• root Version: 5.06/00

In particular I don't see any effect on the two canvases: I didn't find a way to bring the selected canvas in front of the other after the creation of the two canvases.

Thanks in advance.
Cheers
Diego