I am relatively new to this sort of thing and I currently use a different language but reading this thread makes me wonder if there is an issue with using session variables? I am upgrading a program that currently uses POST method to transfer small portions of data between screens and I want to reduce the number of screens and to do this I need to transfer larger data sets. Using Session variables seem like a better idea since they are more persistent and are there through the whole session. For the original poster it would seem that it would be easy to check the session variable to see if it exists and if it doesn't then calculate it otherwise use the session variable and continue? Seems like a simple bug to fix to me. But I only have experience with PHP with this at this point and am still learning. I have not even attempted to learn ASP.