title: get asp:textbox value in client side using javascript function doesn't work
body: <p>This code doesn't display the value, I don't know why?</p>
  
  <p>I have server control:</p>
  
  <pre><code>&lt;asp:TextBox ID="txtTest" runat="server" Visible="false" TextMode="MultiLine"
                      Rows="3" Columns="23" CssClass="white-scroll" /&gt;
  </code></pre>
  
  <p>in javascript function:</p>
  
  <pre><code>var eventText = document.getElementById('&lt;%=txtTest.ClientID%&gt;').value;
  alert (eventText);
  </code></pre>
  
  <p>I enter text then click on button that call the javascript function, but the alert box doesn't display the entered text.</p>
  
  <p>EDIT: when I initialize the text with Text="some text", it is displayed in alert, I want to enter text in client side and get the value of it in the Javascript function.</p>
  
  <p>Thanks</p>