State Management :: Clear The Session When Pass From One Page To Another?

I have a report parameter page which contains many pop up windows for the parameter selection. For example, for driver , there is a pop up window called driver.aspx which contains a listbox that contains list of driver's name.

Now, for each of these pop up windows, i am passing the values of these windows as a session value.

Now, when a user logs in the system, there are many parameter pages for different reports which commonly share the same pop up windows if the parameters are same for different reports.

The problem now is,a user selects 10 drivers for report 1 and runs it. When he goes to report 2 and runs the report, the report 2 takes only those 10 drivers as the driver parameter value.

It means, the error can arise on the system because he may forgot that he have selected 10 drivers for previous report 1. User will not have time to recheck each previous selected values of different paramaters.

What i want is, when a person moves from one report page to another, i want to clear all the session values and adjust it as default for the new report .