getting the result from a list

Hi,

I'd like to get the result from a list in a choose from list object but instead of getting the string returned, I'd like to get the index selected.

I found some example like this one :

set theList to {"A", "B", "C", "D"}
set theChoice to (choose from list theList) as string
set n to 0
repeat with i from 1 to number of items in theList
  set x to item i of theList
  set n to n + 1
  if x is theChoice then exit repeat
end repeat
return n

But it's not a good idea to do that because if two items have the same name, the script failed to return the good index :

set theList to {"B", "B", "C", "D"}
set theChoice to (choose from list theList) as string
set n to 0
repeat with i from 1 to number of items in theList
  set x to item i of theList
  set n to n + 1
  if x is theChoice then exit repeat
end repeat
return n

Select the item 2 but index 1 is returned.

Thx a lot.