title: textboxs aren't updating when I select a new option from combo box c#
body: <p>My code is this: </p>
  
  <pre><code>if (comboBox5.Text == "Primer")
  {
      richTextBox5.Text = "This is the number of primer tins" + primer.ToString();
  }
  if (comboBox3.Text == "Matt")
  {
      richTextBox6.Text = "This is how many 2.5 tins of paint are needed: " + val44.ToString();
  }
  if (comboBox3.Text == "Vinyl")
  {
      richTextBox6.Text = "This is how many 2.5 tins of paint are needed" + val55;
      richTextBox3.Text = valcm.ToString();
  }
  if (comboBox3.Text =="Silk")
  {
      richTextBox3.Text = valcostsilk.ToString();
  }
  </code></pre>
  
  <p>The code runs fine, however when I go back to select a new option from the combo box it doesn't update the relevant rich text box. As I say, I am new to this all and any help will be appreciated. </p>