Barry the baldy

OK im going to explain as best i can so please bear with me... Say i have told a heli to go pick up a group and drop them off at a city then hold above the city, and i want to execute a script for the heli while its holding... how do i make the script wait until the heli has done all its work until it executes the script? I hope that made sense... Thanks in advanced for any help.

Aaaaahhhhh perfect thanks... tried everything but missed that command in the command reference. thanks again.