title: Hiding Div on when other div gets visible
body: <p>I have a code below in my aspx page:</p>
  
  <pre><code>&lt;div id="FormContainer"&gt;
                  &lt;div id="leftSection"&gt;
                      &lt;h1&gt;
                          Contact Us&lt;/h1&gt;
                      &lt;div id="intro"&gt;
                          &lt;p&gt;
                              Contact PLI&lt;/p&gt;
                          &lt;p&gt;
                              &amp;nbsp;&lt;/p&gt;
                      &lt;/div&gt;
                      &lt;esp:contactus id="ContactUs" runat="server" /&gt;
                  &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>And some code which comes from my above usercontrol (<strong>esp:contactus</strong>) is given below</p>
  
  <pre><code>    &lt;div id="divMain" runat="server"&gt;
          &lt;div class="leftColumn"&gt;
          &lt;span id="ContactUs_lblFirstName" class="details"&gt;First name:&lt;span class="asterisk" title="This field is mandatory"&gt;*&lt;/span&gt;&lt;/span&gt;
          &lt;input name="ContactUs$txtFirstname" type="text" maxlength="50" id="ContactUs_txtFirstname" /&gt;
          &lt;span id="ContactUs_rfvFirstName" style="color:Red;visibility:hidden;"&gt;Please type your forename here&lt;/span&gt;
          &lt;span id="ContactUs_lblFamilyName" class="details"&gt;Family name:&lt;span class="asterisk" title="This field is mandatory"&gt;*&lt;/span&gt;&lt;/span&gt;
          &lt;input name="ContactUs$txtFamilyName" type="text" maxlength="50" id="ContactUs_txtFamilyName" /&gt;
          &lt;span id="ContactUs_rfvFamilyName" style="color:Red;visibility:hidden;"&gt;Please type your family name here&lt;/span&gt;
  
          &lt;span id="ContactUs_lblAddress1" class="details"&gt;Address 1&lt;span class="asterisk" title="This field is mandatory"&gt;*&lt;/span&gt;&lt;/span&gt;
          &lt;input name="ContactUs$txtAddress1" type="text" maxlength="50" id="ContactUs_txtAddress1" /&gt;
          &lt;span id="ContactUs_rfvAddress1" style="color:Red;visibility:hidden;"&gt;Please enter the first line of your address&lt;/span&gt;
          &lt;span id="ContactUs_lblAddress2" class="details"&gt;Address 2&lt;/span&gt;
          &lt;input name="ContactUs$txtAddress2" type="text" maxlength="50" id="ContactUs_txtAddress2" /&gt;
  
  &lt;asp:button id="btnSubmit" cssclass="submitBTN" text="Submit"
                  onclick="Submit_Click" runat="server" /&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  
  &lt;div id="divThanksmsg" runat="server"&gt;
          Thank you for your enquiry.
      &lt;/div&gt;
  </code></pre>
  
  <p>If you see there is submit button in my usercontrol, after validating all above fields its display the thankyou div (divThanksmsg). </p>
  
  <p>when user clicks on submit button it is validating all the form after validating fields my thankyou div (<strong>divThanksmsg</strong>) gets visible. But if you see the above div in my aspx page with id (<strong>intro</strong>) it is visible everytime. I want this div should get hidden when my thankYou div is visible.</p>
  
  <p>Please suggest!</p>