ASP.NET: Yes/No Radio Buttons, If Yes, enable TextBox?
<p>I searched around a few different places for an answer and checked topics <a href="https://stackoverflow.com/questions/10800976/how-to-handle-many-yes-no-if-yes-display-textbox-on-form">like this</a>, but was not able to find an applicable answer.</p>

<p>I'm creating a web application for a paper form (much like the user in the link I posted). However, unlike that user I'm NOT using an update panel for the display. His post wasn't descriptive enough for me to figure out how to replicate what he had done to get it working.</p>

<p>All I want to do is have an asp RadioButtonList; when "Yes" is checked, enable "Reported Date" (see below for how it looks currently on the form); "Else" disable it.</p>

<p><a href="https://i.stack.imgur.com/DwkMY.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/DwkMY.png" alt="enter image description here"></a></p>

<pre><code>   &lt;div class="col-xs-6 text-right"&gt;
                        &lt;b&gt;Reported to a Supervisor?&lt;/b&gt;&lt;br&gt;
                    &lt;/div&gt;
                    &lt;asp:RadioButtonList ID="RadioButtonList_ReportedToSupervisor" runat="server"
                        RepeatDirection="Horizontal"&gt;
                        &lt;asp:ListItem Text="Yes" Value="1"&gt;&lt;/asp:ListItem&gt;
                        &lt;asp:ListItem Text="No" Value="0"&gt;&lt;/asp:ListItem&gt;
                    &lt;/asp:RadioButtonList&gt;
                    &lt;br&gt;
                    &lt;div class="col-xs-6 text-right"&gt;
                        &lt;b&gt;Reported Date:&lt;/b&gt;&lt;br&gt;
                    &lt;/div&gt;
                    &lt;div class="col-xs-6"&gt;
                        &lt;asp:TextBox
                            runat="server"
                            ID="TextBox_ReportedDate"
                            class="form-control"
                            style="max-width:125px" /&gt;
                        &lt;asp:RegularExpressionValidator
                            ID="RegularExpressionValidator_ReportedDate"
                            runat="server"
                            ControlToValidate="TextBox_ReportedDate"
                            ErrorMessage="Invalid date"
                            ValidationExpression="^^((0[1-9])|(1[0-2]))\/((0[1-9])|(1[0-9])|(2[0-9])|(3[0-1]))\/(\d{4})$"
                            Display="Dynamic"
                            SetFocusOnError="True"
                            Font-Bold="true"
                            ForeColor="red" /&gt;
                        &lt;ajaxToolkit:MaskedEditExtender ID="maskededitextender_ReportedDate" runat="server" TargetControlID="TextBox_ReportedDate" Mask="99/99/9999" MaskType="Date" AcceptNegative="None" /&gt;
                    &lt;/div&gt;
</code></pre>

<p>I'm very new to building web applications so I apologize if this is a relatively dumb question. I am not familiar enough with the common ASP.NET controls in order to figure this out myself.</p>

<p>Thank you very much!</p>