ASP.NET

int n;
if(!int.TryParse(EnterByUserTextBox.Text, out n))
{
    // Inform user about invalid input and return
}

// using block avoids resource leaks
using(SqlConnection sconn1 = new SqlConnection(connectionstring))
using(SqlCommand scomm1 = sconn1.CreateCommand())
{
     // Adding parameters
     scomm1.Parameters.AddWithValue("@pid_no", lblprint_id.Text);
     scomm1.Parameters.AddWithValue("@pserial_no", lblserial_no.Text);
     scomm1.Parameters.AddWithValue("@ppassword", lblpassword.Text);
     try
     {
         sconn1.Open();
         for (i = 1; i <= n; i++)
         {
              scomm1.ExecuteNonQuery();
         }
         sconn1.Close();
         lblmsg.Text = "Successfully Created";
         update();
     }
     catch(Exception ex)  // always catch specific exceptions than the base System.Exception
     {
         lblmsg.Text = "Please Try Again" + ex.ToString();
     }
}

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