I have passed account in Imperspnate and my site is down--urgent

Hi All

Due to come COM objects issue, I tried to give impersonate='"true" which i a default and i passed an username, pass in that . I am not able to open my site now.

Error msgs :

 
Line 1: <%@ Assembly Name="Microsoft.SharePoint"%><%@ Application Language="C#" Inherits="Microsoft.SharePoint.ApplicationRuntime.SPHttpApplication" %>

Can some plz hep let me on this.

Thanks & regards

Rakesh