Setting text item delimiters in Cocoa-Applescript App

Question

Does anyone know of a problem with text item delimiters in a Cocoa-Applescript App.  This is in Xcode 4.5.2 and  Mountain Lion
the following code seems to fail  to set the text item delimeter  to + when I run it in Coca-AppleScript
--  TSTAppDelegate.applescript
--  Test Text item Delimiters
--  Created by Frank Caggiano on 12/22/12.
--  Copyright (c) 2012 Frank Caggiano. All rights reserved.
script TSTAppDelegate
  property parent : class "NSObject"
          on applicationWillFinishLaunching_(aNotification)
  -- Insert code here to initialize your application before any files are opened
        tstTxtDel()
          end applicationWillFinishLaunching_
          on applicationShouldTerminate_(sender)
  -- Insert code here to do any housekeeping before your application quits
                    return current application's NSTerminateNow
          end applicationShouldTerminate_
    on tstTxtDel()
        set text item delimiters to "+"
        set d to "-s http://www.nietzschefamilycircus.com"
        set r to do shell script "curl  " & d & " | ~/Desktop/try.pl"
        display dialog "r is " & r
        set rr to every text item of r
        display dialog "rr " & rr
        display dialog "curl " & first text item of rr & " -o "
end
end script
However if you put the tstTstDel() function in the Applescript editor it works as expected.
The try.pl script is
#!/usr/bin/perl
$s ="";
while (<>) {
    $s .= $_;
$s =~ m{class="comic"(.*)<div class="footer">}si;
($link, $caption,$jj) = ($1 =~ m{<img src="(.*)" alt=.*class="quote">(.*)(</div>.*</div>)}si);
print $link, "+", $caption, "\n";
I know this worked in the past. The Coca-Applescript app was written at least as far back as Snow Leopard. The site I am parsing changed their format and I was updating the app as a means to learn the new Coca-Applescript environment.
Any help appreciated

Answer 1

OK found it, I needed to use
set Applescript's text item delimiters to "+"
instead of just
set text item delimiters to "+"
I suppose it is a scoping thing.