What makes a line a line in a chunk expression?

[Len Morgan]

I'm trying to go to a card based on the choice made in an option menu 
and it's not working right.  Here's the gist of what I'm doing:

on menuPick pChoice
    put the text of button "taskBar" into tChoices
    if pChoice is among the lines of tChoices then
        go to card pChoice
    end if
end menuPick

For some reason, this doesn't work.  Is pChoice not a line?  Since some 
of the cards have multi-word names, I can't use "word".  Am I missing 
something?

len morgan