Adding print slide or window button

I am trying to print the quiz results page and the only thing I can find is to add a smart shape button and change the action to "execute_JavaScript".  In the script_window i'm simply adding one line of code "window.print()".  The problem I'm running into is when I publish my project the slide containing the print button shows up completely blank.  Any idea whay I am doing wrong here?  I tried adding a widget as well, but my system does not have a print widget available.