File Open Execute and Save

Response.AppendHeader(@"Content-Disposition", "attachment; filename=" + obj.dr["filepath"].ToString());
Response.ContentType = "application/zip";
Response.WriteFile(obj.dr["filepath"].ToString());
Response.End();

It is taking path as the folder where my project is saved i.e. D:\Mentor\MentorLocal but i want the path it should take is D:\Mentor\MentorLocal\Docs where the files i have saved.....so how to set the path...coz it says that the D:\Mentor\MentorLocal does not have the specified fil ...