disable table control field

Hi Experts,

I have create a module pool program where in there is a table control with some fields. I had a requirement where I need to disable all the tablecontrol fields when I click DISPLAY button. ( Display button ).

loop at screen.
 if screen-group1 = 'GR'.
 if sy-ucomm = 'CHANGE'.
 screen-input = 1.
 screen-input = 0.      " when clicked DISPLAY button.

My problem is only menge ( Quantity) field is not disabling.

please provide your suggestions.

Thanks and Regards

Murali Krishna. T