SCRIPT ERROR! Plz help

I need to know how to make my characters Emma and Zack walk down the school hallway at the same time with camera following Emma is doing the action exhausted and Zack is walking normally to zone 3

&ZACK walks to spot (x,y,z) in (time)
@follow EMMA to (screen x in zone (1,2,3 ) in time) AND EMMA does it while walk_exhausted

When I tried that Zack arrived before emma

Make sure they walk in the same time interval.

Thx