private void rbResidential_CheckedChanged(object sender, EventArgs e) { // When Residential radio button is checked // We disable the second KWH entry box and ask the user to enter regular KWH // Change the labels lblKWH1.Text = "Enter kWh Used:"; lblKWH2.Text = ""; // Clear the two KWH entry boxes txtKWH1.Text = ""; txtKWH2.Text = ""; // Set the tags for the KWH entry boxes txtKWH1.Tag = "Enter kWh Used"; txtKWH2.Tag = ""; // Enable the first entry box, but disable the second one txtKWH1.ReadOnly = false; txtKWH2.ReadOnly = true; // Provide the Residential description in the rich text box rtbCustDesc.Text = Residential.CustomerDescription(); }