You realize asp.net uses form postback. Typically you will have something like
if not page.isPostback then
'' Display default values for elements
'' Read the request.form variables and processes the values
eg.... dropdownvalue=request("myDropdown") & ""
asp.net can serve up different markup and scripts for different browser versions, and IE6 has different security zone settings (which can affect how form posts are sent back to the server), so the comparison to IE6 is useless without a sample.