title: Javascript: How to get the ClientID of the button that was clicked?
body: <p>Here's the button.</p>
  
  <pre><code>&lt;asp:Button ID="_btnSearch" Text="Search" onclientclick="return CheckForEmptySearchBox(this.ClientID)" /&gt;
  </code></pre>
  
  <p>And here's the Javascript function</p>
  
  <pre><code>&lt;script type = "text/javascript"&gt;
          function CheckForEmptySearchBox(id) {
             alert("The ID of the button is: " + id)
  
             return false;
          }
  &lt;/script&gt;
  </code></pre>
  
  <p>I'm getting a alert box, saying "The ID of the button is: <strong>undefined</strong>"</p>
  
  <p>Thanks for helping</p>