Code below has 1 major and 1 minor problem. Major issue is, once you push the button it visually stays pushed. Minor problem is, I run this in Cygwin. I've got an rxvt window behind the Tk window.

However, I had written the code in Python, so I had to make a choice. The Tkinter toolkit lets you create widgets (like buttons, for example) and give them a parent, such as a window or a frame.