Added variable to work with

Started to write my own variables and functions…including the
Math.random
Cleaning up original alerts

As I started to write the program I needed some help, so I started
watching the video. This is when I cleaned up the code a bit.
Added the function winnerCheck()

I followed the video to add the function winnerCheck()
Added the alert for each round

This will alert as to what the health of each player is until finally
there is result no winner is false.
Added comments

These comments ensure that I know what the program is doing.