registration limit using asp.net c#

protected void Button1_Click(object sender, EventArgs e)
   {



       if (temp == 0)
       {
           try
           {
               SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["registrationConnectionString"].ConnectionString);
               conn.Open();
               string insertquerry = "insert into userdata(VerificationNumber,FirstName,LastName,Gender,Birthday,CivilStatus,EmailID,MobileNumber,Address,DateRegistered,ExamSchedule) values (@VERIFY ,@FN ,@LN ,@GENDER ,@MONTH ,@CS ,@EMAIL ,@CP ,@ADRESS ,@DATE ,@SCHED)";
               SqlCommand com = new SqlCommand(insertquerry, conn);
               com.Parameters.AddWithValue("@VERIFY", TextBoxVERIFY.Text);
               com.Parameters.AddWithValue("@FN", TextBoxFN.Text);
               com.Parameters.AddWithValue("@LN", TextBoxLN.Text);
               com.Parameters.AddWithValue("@GENDER",              DropDownListGENDER.SelectedItem.ToString());
               com.Parameters.AddWithValue("@MONTH", TextBoxBD.Text);
               com.Parameters.AddWithValue("@CS", DropDownListCS.SelectedItem.ToString());
               com.Parameters.AddWithValue("@EMAIL", TextBoxEMAIL.Text);
               com.Parameters.AddWithValue("@CP", TextBoxCP.Text);
               com.Parameters.AddWithValue("@ADRESS", TextBoxADRESS.Text);
               com.Parameters.AddWithValue("@DATE", LabelTIME.Text);
              LabelTIME.Text = DateTime.Now.ToString();
              com.Parameters.AddWithValue("@SCHED", DropDownListSCHED.SelectedItem.ToString());


               com.ExecuteNonQuery();

               StreamWriter thepath = new StreamWriter("C:\\inetpub\\ftproot\\reg.txt", true);

               using (StreamWriter writer = (thepath))
               {
                   writer.WriteLine("[" + TextBoxFN.Text + "]" + "[" + TextBoxLN.Text + "]" + "[" + TextBoxVERIFY.Text + "]" + "[" + DropDownListGENDER.SelectedItem.ToString() + "]" + "[" + TextBoxBD.Text + "]" + "[" + DropDownListCS.SelectedItem.ToString() + "]" + "[" + TextBoxEMAIL.Text + "]" + "[" + TextBoxCP.Text + "]" + "[" + TextBoxADRESS.Text + "]" + "[" + LabelTIME.Text + "]" + "[" + DropDownListSCHED.SelectedItem.ToString() + "]");


               }


               {
                   Session["VerificationNumber"] = TextBoxVERIFY.Text;
               }

               Response.Redirect("registersuccess.aspx");

               conn.Close();
           }
           catch (Exception ex)
           {
               Response.Write("Error:" + ex.ToString());
           }
       }

   }