You cannot effectively combine the "toy" scripting tools prompt() and alert() and document.write( ) with form fields such as buttons and checkboxes and such.
If you want to start using buttons and such, then it's time to start creating *real* HTML pages instead of toy learning tools.
You *could* create the button, yes, but it couldn't very well interact with your prompts and such.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.