How to prevent if cache using jquery

var iframe_url = 'http://www.wala.com/';
var cacheParamValue = (new Date()).getTime() * 1000;
var url = iframe_url + "?cache=" + cacheParamValue;
jQuery( 'iframe' ).attr( 'src', url );  

Output:

<iframe width="100%" height="99%" src="http://www.wala.com/?cache=1406685294271000"></iframe>