Object reference not set to an instance of an object.

at index.Page_Load(Object sender, EventArgs e) in c:\webs\AA\aaq2\index.aspx.cs:line 16
at System.Web.UI.Control.LoadRecursive()
at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)