title: how to run method after check box is checked
body: <p>I am building a form on an aspx page. I want to run a method that will add more fields and labels if the user ticks a checkbox labeled 'recurring donation?'</p>
  
  <p>My Form </p>
  
  <pre><code>        &lt;telerik:LayoutRow CssClass="formContainer"&gt;
              &lt;Columns&gt;
                  &lt;telerik:LayoutColumn Span="12" SpanSm="12" SpanMd="12"&gt;
                      &lt;asp:Label id="firstName" runat="server"&gt;&lt;/asp:Label&gt;
                      &lt;br /&gt;
                      &lt;asp:TextBox runat="server" ID="UserFirstName"&gt;&lt;/asp:TextBox&gt;
                  &lt;/telerik:LayoutColumn&gt;
                  &lt;telerik:LayoutColumn Span="12" SpanSm="12" SpanMd="12"&gt;
                      &lt;asp:Label id="lastName" runat="server"&gt;&lt;/asp:Label&gt;
                      &lt;br /&gt;
                      &lt;asp:TextBox runat="server" ID="UserLastName"&gt;&lt;/asp:TextBox&gt;
                  &lt;/telerik:LayoutColumn&gt;
                  &lt;telerik:LayoutColumn Span="3" SpanSm="12" SpanMd="12"&gt;
                      &lt;asp:Label id="address1" runat="server"&gt;&lt;/asp:Label&gt;
                      &lt;br /&gt;
                      &lt;asp:TextBox runat="server" ID="userAddress1"&gt;&lt;/asp:TextBox&gt;
                  &lt;/telerik:LayoutColumn&gt;
                  &lt;telerik:LayoutColumn Span="9" SpanSm="12" SpanMd="12"&gt;
                      &lt;asp:Label id="address2" runat="server"&gt;&lt;/asp:Label&gt;
                      &lt;br /&gt;
                      &lt;asp:TextBox runat="server" ID="userAddress2"&gt;&lt;/asp:TextBox&gt;
                  &lt;/telerik:LayoutColumn&gt;
                  &lt;telerik:LayoutColumn Span="3" SpanMd="12" SpanSm="12"&gt;
                      &lt;asp:Label ID="city" runat="server"&gt;&lt;/asp:Label&gt;
                      &lt;br /&gt;
                      &lt;asp:TextBox runat="server" ID="userCity"&gt;&lt;/asp:TextBox&gt;
                  &lt;/telerik:LayoutColumn&gt;
                  &lt;telerik:LayoutColumn Span="9" SpanMd="12" SpanSm="12"&gt;
                      &lt;asp:Label ID="zip" runat="server"&gt;&lt;/asp:Label&gt; 
                      &lt;br /&gt;
                      &lt;asp:TextBox ID="userZip" runat="server"&gt;&lt;/asp:TextBox&gt;
                  &lt;/telerik:LayoutColumn&gt;
                  &lt;telerik:LayoutColumn&gt;
                      &lt;asp:Label ID="returningDonor" runat="server"&gt;&lt;/asp:Label&gt;
                      &lt;br /&gt;
                      &lt;asp:CheckBox ID="userReturningDonor" runat="server" /&gt;
                  &lt;/telerik:LayoutColumn&gt;
              &lt;/Columns&gt;
          &lt;/telerik:LayoutRow&gt;
  </code></pre>
  
  <p>
  And my code behind</p>
  
  <pre><code>public partial class donationForm : System.Web.UI.Page
  {
      protected void Page_Load(object sender, EventArgs e)
      {
          firstName.Text = "First Name";
          lastName.Text = "Last Name";
          address1.Text = "Address 1";
          address2.Text = "Address 2";
          city.Text = "City";
          zip.Text = "Zip Code";
          returningDonor.Text = "Recurring Donation?";
  
          userReturningDonor.Checked = showRecuring();
      }
      static void showRecuring()
      {
          /*RUN CODE*/
      }
  }
  </code></pre>
  
  <p>The error im getting is </p>
  
  <blockquote>
    <p>Cannot implicity convert type 'void' to 'bool'</p>
  </blockquote>