Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

protected void btnuppersonal_Click(object sender, ImageClickEventArgs e)
   {
       //string finduser = Request.QueryString["ids"].ToString();
       SqlConnection cn = new SqlConnection(ConfigurationManager.AppSettings["constring"].ToString());
       //SqlConnection cn = new SqlConnection(ConfigurationManager.ConnectionStrings["Connection"].ConnectionString);
       cn.Open();
       SqlCommand cmd = new SqlCommand();
       cmd.CommandText = "puppersonal";
       cmd.CommandType = CommandType.StoredProcedure;
       //cmd.Parameters.AddWithValue("@userid", Convert.ToInt32(Session["finduser"].ToString()));
       cmd.Parameters.AddWithValue("@userid", Convert.ToInt32(Session["pids"].ToString()));
       cmd.Parameters.AddWithValue("@fname", txtfname.Text);
       cmd.Parameters.AddWithValue("@lname", txtlname.Text);
       cmd.Parameters.AddWithValue("@gender", ddlgender.SelectedItem.Text);
       cmd.Parameters.AddWithValue("@altemailid", txtaltemail.Text);
       cmd.Parameters.AddWithValue("@mobile", txtmobile.Text);
       cmd.Parameters.AddWithValue("@phone", txtphone.Text);
       cmd.Parameters.AddWithValue("@address", txtaddress.Text);
       cmd.CommandTimeout = 0;
       cmd.Connection = cn;
       cmd.ExecuteNonQuery();   // Error Line
       cn.Close();
       //clear();
       Page.ClientScript.RegisterStartupScript(this.GetType(), "Updated", "<script>alert('Yor Pesonal details Updated sucessfully')</script>");

       txtfname.Text = "";
       txtlname.Text = "";
       ddlgender.SelectedItem.Text = "";
       txtaltemail.Text = "";
       txtphone.Text = "";
       txtaddress.Text = "";
   }