file organization
wrap everything in a self-executing anonymous function

to prevent from accidentally creating and using global variables
use an array for the images
use comparison operators that check the types
remove trailing whitespace
fix indentation
better name for images: diceImg
use an array for the dice
pull canvas and ctx variables out since they are not modified
html indentation
rename draw() to start()
no need for start() function now that code is at end of body
rename ctxMove to takeOneTurn
collapse the dice logic