private void cbxType_SelectedIndexChanged(object sender, System.EventArgs e)
        {
            txtSize.ReadOnly = !cbxType.CurrentSelectAllowChangeSize();
            int n = cbxType.CurrentSelectDataSize();

            if (n == 0)
            {
                txtSize.Text = "";
            }
            else
            {
                txtSize.Text = n.ToString();
            }
        }
 private void cbType_SelectedIndexChanged(object sender, System.EventArgs e)
 {
     if (item != null)
     {
         if (cbType.SelectedIndex >= 0)
         {
             txtSize.ReadOnly = !cbType.CurrentSelectAllowChangeSize();
             int n = cbType.CurrentSelectDataSize();
             if (n == 0)
             {
                 txtSize.Text = "";
             }
             else
             {
                 txtSize.Text = n.ToString();
             }
             fields[item.Index].OleDbType = cbType.CurrentSelectOleDbType();
         }
         item.SubItems[1].Text = cbType.Text;
     }
 }