How to get the number of available passengers? Thread - TrAInsported

HI!

How can I find the list of passengers such of the Tutorial 4. ai.foundPassenger part

    pass = nil 
    i = 1
    while i <= #passengers do
      -- some code to find the nearest passenger and save it to pass variable
     end
     return pass
end

But when I tried it on ai.chooseDirection it returns a error somthing like "cannot get the length of a global passengers (a nil value)"

any suggestions is highly appreciated.

Thanks!