Getting textbox value in javascript code after onchange
<p>On my page, I'm using textbox with calendar extender to get the date value.
I've added <code>onchange="ValidateStartDate();"</code> to the textbox.</p>

<pre><code> &lt;asp:TextBox ID="TextBoxStartDate" runat="server"  ForeColor="Red"    
     onchange="ValidateRsmStartDate();"&gt; 
     &lt;/asp:TextBox&gt;               

&lt;asp:CalendarExtender ID="CalendarExtenderStartDate" 
  TargetControlID="TextBoxStartDate"
  BehaviorID="ceStartDate"  
  PopupButtonID="CalendarExtenderStartDatePopup"                                                                     
  Format="MM/dd/yyyy" runat="server"&gt;
  &lt;/asp:CalendarExtender&gt;

&lt;img class="Spacer" id="CalendarExtenderStartDatePopup" src="Images/Calendar.png"                                                                                
   alt="Start Date" /&gt;
</code></pre>

<p>My javascript function:</p>

<pre><code>function ValidateStartDate() {
   var txtDate = document.getElementById('&lt;%=TextBoxStartDate.ClientID  %&gt;');
   alert(txtDate.innerHTML);
}
</code></pre>

<p>But on <code>alert()</code>, I get no value at all.</p>
