how to submit drop down value after click of button : <p>below coding works fine</p>

<pre><code>&lt;html&gt;
&lt;head&gt;
&lt;/head&gt;
&lt;body&gt;
&lt;select name="menu" id="menu"&gt;
&lt;option value="http://www.google.com"&gt;ESPN&lt;/option&gt;
&lt;option value="http://www.facebook.com"&gt;CNN&lt;/option&gt;
&lt;/select&gt;
&lt;script type="text/javascript"&gt;
 var urlmenu = document.getElementById( 'menu' );
 urlmenu.onchange = function() {
      window.open( this.options[ this.selectedIndex ].value );
 };
&lt;/script&gt;
&lt;/body&gt;
&lt;/html&gt;
</code></pre>

<p>I need to add a button next to drop down which should allow link to work after clicking the button.</p>
