Hi Piller,
That isn't the code where the containers are defined by you, but the transfer of items to the containers. What it is doing is testing if the various containers have been defined already or not (not defined will have the value N/A).
So what you are describing and the code you have selected are not the same place in the script. If you are unsure how to locate the code, then learn to use the commands in EUO to step through the code to find it:
F7 = advance 1 line and pause
F8 = step over a line (usually used for call or gosub statements, where you want to have it run the whole subroutine because you have already cleared it to not have your issue)
F6 = run to the end of the current routine and pause when you get to the next line after the call/gosub statement to execute this routine