protected void Button1_Click(object sender, EventArgs e) { clsbusslayer obj = new clsbusslayer(); String role = obj.login(TextBox1.Text, TextBox2.Text); if (role == "null") { Response.Write("<SCRIPT>alert('Username or password Is incorrect')</SCRIPT>"); } else { DataClassesDataContext rt = new DataClassesDataContext(); employee_registration er = new employee_registration(); employee_master em = new employee_master(); em = rt.employee_masters.Single(employee_master => employee_master.username == TextBox1.Text); Session["emp_code"] = em.emp_code; er = rt.employee_registrations.Single(employee_registration => employee_registration.employee_code == em.emp_code); Session["emp_name"] = er.full_name; switch (role) { case "doctor": Response.Redirect("~/doctor_module/doctor.aspx"); break; case "admin": Response.Redirect("~/admin_home.aspx"); break; case "nurse": Response.Redirect("~/nurse_module/Default.aspx"); break; case "pathologist": Response.Redirect("~/pathology/pathology_home.aspx"); break; default: Response.Write("<SCRIPT>alert('Username or password Is incorrect')</SCRIPT>"); break; } } }