405718 Need help debugging JS overl 2

We have coded a JavaScript system to overlay a layout for different pages, based on a cookie value. We have implemented a JS error log system to detect if the user's browser has experienced trouble running our JS code. We have 2 different layouts for checkout page: A version: gathers complete customer name and address B version: gathers just customer name and zip/postal code A version layout is applied to all the pages. Then, if the cookie value is set to B, the B version layout is applied over A. According to checkout logs: some B version users are sending their complete address, when they are supposed to send along just their names and zip/postal codes. No JS errors have been logged from the checkout page, and we have tested the B layout without problem. We need the assistance of a JS expert to track down this issue. Be aware that: We are running a custom JS code, and we won't be able to use any JS framework. Main browser we are targeting is IE. First logs showed that IE8 .NET 3.0.30729 was the browser logging incorrect customer data, but recent logs shows that at least Chrome has shown the same problematic behavior. Our JS error log system won't work directly at Chrome ([login to view URL]). If someone has the right level of experience and can start quickly, we will end project bidding immediately and select you. Please be ready to start immediately. Please include the word "Excel" in your bid comments so that I know you have read and understand this project description.