You don't handle the `exit` word at all. In the input section, you will probably have to add an if case to output the "Thanks for playing" part.
I guess the problem in the conversion is the way you end the program. Do you hide the button, once exit has been given as input ? Do you leave the button, but make it not react anymore to any click event ? I guess that this is the kind of problems @JohnAD wanted to raise.
