JavaScript Intranet vs Extranet Version 7.3?

Looking for some assistance with an Intranet vs Extranet issue. We are currently using Version 7.2.d. I am wondering if we upgrade to Version 7.3 if that might help solve our issue. It seems I read somewhere that 7.3 solved some of the cross browser compatibility issues. If anyone has experienced this issue and could share how they resolved it, I would greatly appreciate it! Thank you!....Here is our issue.

We have some javascript code on an asp page that is hiding panels on the screen.

The code appears to work fine in the Extranet environment. However, it is not working in the Intranet environment. It seems to me that it would be more likely to be the opposite (ie. work in the Intranet environment and not the extranet environment). Both system are using IE 11. The code works find in Chrome on each system. However, we need to make sure it works in IE 11.

Is there someplace I can look to help troubleshoot why this is happening?

Any assistance would be greatly appreciated! Thank you!