GetValue ( Get(TriggerTargetPanel); 2)
Should return the object name. Did you use the inspector to name each panel in the tab control? This isn't the tab label text you assign to the tab in tab control set up. It's a name given by selecting the tab panel (click once to select the tab. Click again to select the panel.) and entering a name into the Name box in the Inspector.
That was it… still have a lot to learn ;)