Using Speed for Attack

I'm working on a move that uses the user's speed instead of attack, unfortunately this line is throwing up an error for some reason:
Can I simply not use speed stat increases as an attack increase, or am I doing something wrong?

Black Temple Gaurdian said:

Code:

atkstage=attacker.stages|PBStats::SPEED]+6

Click to expand...

Syntax error: you're using a vertical bar instead of an open square bracket. :)

Doy! Thanks!