How do I pause a windows.setInterval in javascript?
<p>I have a javascript function that is called every 2000ms.  I want to pause this so I can have the user do other things on the page without it being called again.  Is this possible?  Here is the function that gets called every 2000ms:</p>

<pre><code>window.setInterval(function getScreen (sid) {
        if (window.XMLHttpRequest)
        {// code for IE7+, Firefox, Chrome, Opera, Safari
          xmlhttp=new XMLHttpRequest();
        }
        else
        {// code for IE6, IE5
          xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
        }
        xmlhttp.onreadystatechange=function()
        {
        if (xmlhttp.readyState==4 &amp;&amp; xmlhttp.status==200)
          {
            document.getElementById("refresh").innerHTML=xmlhttp.responseText;
          }
        }
        xmlhttp.open("POST","getScreen.php?sid="+&lt;?php echo $sid; ?&gt;,true);
        xmlhttp.send();
    },2000);
</code></pre>
