No matter How quickly I release the key, the whole screen will be written to black, then recover to white. I mean I just don't want to make the whole screen white or black at one time.
It's a bit hard to guess what's going wrong with your code without seeing it. If you email it to me (More button: Reply to Author) I'll be happy to look at it for you. Please don't post it on the forum; it's against forum etiquette to post entire programs/hdls.