CRMOD forces to re-login while redirected to ContactHomePage via JSP

We have a JAVA servelet which does a preliminary search on the Contact Module, on the basis of Work Phone #.

If the search returns a contact, then an activity is created for the particular contact.

If the search doesn't return any contact, then the User needs to be re-directed to the Contact Home Page.

Now, the problem we are facing is that CRMOD forces to re-login after redirection from the JSP to the Contact Home Page.

The code for re-direction looks like this.

response.sendRedirect("https://secure-<ServerInstance>.crmondemand.com/OnDemand/user/ContactHomePage" );" );

Now i even tried appending the JSessionID at the end of the URL, like this