Scratch

Well, it is actually pretty easy; all you need is a loop and the mod block.

I didn't test this script, it's off the top of my head, but it should work. 

set [num1 v] to [0] // The first number
set [num2 v] to [0] // The second number
if <(num1) > (num2)>
 set [dir v] to [1]
else
 set [dir v] to [0]
end
repeat until <<<((num1) mod (num2)) = [0]> and <(dir) = [1]>> or <<((num2) mod (num1)) = [0]> and <(dir) = [0]>>>
 if <(dir) = [0]>
  set [num1 v] to ((num1) mod (num2))
  set [dir v] to [1]
 else
  set [num2 v] to ((num2) mod (num1))
  set [dir v] to [0]
 end
end
if <(dir) = [0]>
 set [answer v] to (num2)
else
 set [answer v] to (num1)
end

Gravitation wrote:

I made a mistake in the above script and reported it to be fixed since I can't edit yet. Sorry 'bout that, i switched the num1 and num2 reporters in the last if/else. If you see "last edited by" in italics at the bottom of the psot, it has been fixed. 

Why don't you make some projects to be a Scratcher?

[offtopic]Look at the text in red. TBG time!  [/offtopic]