Challenge: Mouse movement mania

 is a programming challenge in the Intro to JS course. This challenge practices making interactive programs using  and

Steps
There are three steps in this challenge:
 * 1) Add a   command: This step asks users to add a   command that contains   and   variables for the parameters.
 * 2) Change the   command: This step asks users to change the   command so it contains   and   variables for the width/height parameters.
 * 3) Add a   command: This step asks users to remove the   add a   command inside the   function that contains   and   variables for the parameters.

If users get stuck
If users get stuck, they should:
 * Pay attention to Oh Noes and the error messages.
 * Go back to the "Interactive programs" tutorial.