Debug/Modify existing banner exchange script

I have a banner exchange script I need debugged and modified. The script is written is cgi/perl. ## Deliverables The modifications I need are "referral levels added to the script. I need a minimum of 5 levels, with each level receiving a percentage of each levels impressions/page views. Percentages as follows level 1 = 10% level 2 = 5% level 3 = 2% level 4 = 1% level 5 = 1% Also, I need this script debugged. Currently when the script runs I get file lock errors and all members info etc... is lost and it's not necessary for anyone to be using the Banner exchange to receive these errors. I need the script thoroughly debugged to make certain it's going to run properly for my members. Any and all enhancements or suggestions would be a tremendous help. Complete source code of all programming work done and rights to the changes.