Dynamically changing the tooltip of a button

[Anonymous]

I have a macroscript that applies the current Material Editor material to objects and it works great. However, it would be even better if the button's tooltip could display the name of the material before I apply it. I guess this would require evaluating it each time the mouse hovers over the button. Is this possible?

macroScript GHassignCurMaterial
  category:"GaryButtons2"
  toolTip:"Apply current matl to selection" 
  ButtonText:"Matl" 
 (
 on execute do
 (
 mtl = meditMaterials
 statusmsg = "MATERIAL: "+mtl.name+" APPLIED TO SELECTION"
 $.material = mtl
 displayTempPrompt statusmsg 3000
 )
)