How to transfer the control from one page to another .cs?

See more:

C#

ASP.NET

if (chkTrustedForm.Checked)
            {
                ViewState["TrustedFormOfferID"] = Request.QueryString["CID"].ToString();
                Server.Transfer("Offer.aspx");
            }

What I have tried:

Hi Guys,
I tried server.transfer and response.redirect and getting

The file '/RM/Admin/Offer.aspx' does not exist

Problem is,In the solution the 'offer' page is outside admin folder and file from where I'am redirecting 'EditCamapign.aspx' is in Admin folder. I tried with response.redirect and server.transfer method but still getting the same error. Please assist me what changes to be made