Actually, packforget is used to make that table invisible, when that button is pressed again. It means at the first press of button table will appear and in the next press of button table will disappear.
Well I cannot comment out my size restrictions, because the moment i do that whole window become so small (of course with scroll), but it does not serve my purpose. I want my first table and following buttons to be shown by default, and when "new names" button is pressed a table should appear with a scrollbar (in main window) having default focus.
I think this will make the things clearer.