public partial class MainForm : Form
 {
     // Indicates the a query is being processed
     Boolean _processing = false;
            
     TdConnection _cn = null;
     String _connectionString = @"Data Source=Teradata1; " +
                "Initial Catalog=ProdDB; " +
                "Integrated Security=True;Pooling=False ";
            
     public MainForm()
     {
         InitializeComponent();
     }
            
     private void WarehouseCallback(IAsyncResult result)
     {
         TdCommand command = (TdCommand)result.AsyncState;
            
         try
         {
            command.EndExecuteNonQuery();
            
            MessageBox.Show("Database has been updated", "Information");
         }
         catch (TdException t)
         {
            MessageBox.Show(t.Errors[0].Message, "ERROR");
         }
         finally
         {
             _processing = false;
            
             _cn.Close();
         }
     }
 
     private void buttonSubmit_Click(object sender, EventArgs e)
     {
         //checking whether the form is already processing 
         //another query
         if (true = _processing)
         {
             MessageBox.Show(
                 "Currently updating warehouse information");
         }
         else
         {
             String warehouseSQL = "Update ProductWarehouse " +
                           "set ProdCount = " + textBoxProdCount.Text +
                           where ProdNo= " + textBoxProdNo.Text;
            
             try
             {
                 _processing = true;
            
                 //The application has already created the
                 //connection object.  The name of the object
                 //is _cn.
            
                 TdCommand command = _cn.CreateCommand();
                 command.CommandText = warehouseSQL;
            
                 //setting up the delegate for the asynchronous call
                 AsyncCallback callback = 
                          new AsyncCallback(WarehouseCallback);
            
                 //asynchronous call.  The WarehouseCallback callback
                 //will be invoked by the provider after processing of 
                 //the query has been completed.
                 command.BeginExecuteNonQuery(callback, command);
             }
             catch (TdException t)
             {
                 MessageBox.Show(t.Errors[0].Message);
            
                 _cn.Close();
             }
         }
     }
 }