Djay - the WHDLoad link to the rawkey codes are correct as they're Amiga keycodes so Escape is 45.
Here's a link to a PDF Blitz manual that should contain everything you need -
http://math.ut.ee/~isotamm/PKeeled/T...Manual-ENG.pdf
The command for checking keypresses is RawStatus. However before you use that you must use the command 'BlitzKeys On' if you're in Blitz mode otherwise it won't work.
So if you want to check for a press of Escape, you'd use 'While NOT RawStatus($45)'.