Fishgame tut collision problem

Hi Im on step 5 of the Fishgame tutorial and Im stuck on the part were the fish is suposed to eat the buble and then the bubble respawns at the top. I have everything checked that the tutorial says. and heres my code.

function FishFood::onCollision(%srcObj, %dstObj, %srcRef, %dstRef, %time, %normal, %contactCount, %contacts)
{
if(%dstObj.class $= "PlayerFish")
{
%srcObj.spawn();
}
}

Need some help plz.