Pro/PROGRAM

Hello community! I am trying to auto generate a pedestal assembly. My question is in assembly mode is it possible to change a component's dimension included in the assembly. I have entered a code like following:

TOP_PLATE_PEDESTAL YES_NO
"Does the pedestal have top plate?:"
IF (TOP_PLATE_PEDESTAL == YES)
TOP_PLT_THK NUMBER
"Enter the top plate dimension:"
END IF

What change should I make to the code so I can vary the thickness of the top plate? (here thk is thickness).