i have 1 master page with 5 pages that call it. now on the master page, I have few dropdowns and textboxes, and the calling pages only have a small article in the corner. I want to start a session on page_load event, so that if the user chooses to select a dropdown or put data in textbox, even if he clicks on the other 4 links of other pages, the data should stay. how can this be done?