There are some problems with the way you posted the code for the "mLeftIndex" subroutine -- missing curly braces and lines of code broken into two or more lines of text where they shouldn't be (including a " +" continuation marker as part of the line break).

Have you checked the script for syntax errors? (run the command perl -T -cw your_script_filename

Have you checked the web server's error log to see whether your script is generating error messages, and what those are?

If the script you are actually running does not contain syntax errors, and if it is not emitting error messages to the server log, please try updating your post with a cleaner and more faithful rendering of the code in question. (Fixing indentation would be a real help as well.)