Let's Make Robots!

PICAXE 28x1 Syntax Error

I need help, I'm trying to program a sonar with the PICAXE programing editor and tere's this Syntax error that shouldn't be there.

low portc 0
pulsout b.5,5
pause 200
pulsin portc 0, 1, w1
w1 = w1/29

It only complains with the "pulsin" line, the "low" line doen't create any sort of problems. What's wrong here?