[mod_python] Detecting Back Button Usage

Hi,

This may not be the list I need, but here goes.  I'm new at this whole 
user interface thing, by nature a low-level systems guy, so be kind.

I'm using mod_python under Ubuntu Edgy 64, doing some basic plots of 
data and allowing users to select a point to center on a region and gen 
the next plot.  All of that works as long as the user moves forward. 
The problem comes in the use of the back button.  The browser merely 
displays the last page rather than rebuilding it, or at least restoring 
the variables.  This leads to a lot of confusion because the server is 
on one set of plot values and the browser is now on another.  This seems 
to be a common problem.  Is there a solution, or should I just warn the 
user not to use the browser back button?

...Thanks,
...Ken