By OutputCache directive you asking to hold the page in cache for 1 second. You need to remove that if you dont want to cache it.

Add these lines in the html meta section

<META HTTP-EQUIV="CACHE-CONTROL" CONTENT="NO-CACHE">
<META HTTP-EQUIV="EXPIRES" CONTENT="0">

and in the page_load write this

Response.Cache.SetCacheability(HttpCacheability.NoCache);

Thanks