PAGE_INIT Event in asp.net

Question

Hi
  In page_load event iam binding data to drop down list
based on the selection of dropdown iam binding questions and answers dynamically keeping value in session.
iam accessing session variable in page_init event for retaining contols again based on the selection of dropdown.

but here problem is iam unable to access the selected value in page_init event
page_init fires before the page_load event.

how to access selected value in page_init event please help me