Liferay refresh portlet with Ajax

function refreshAssetPublisherPortlet() {
   var portletSelector = '.portlet-asset-publisher';
   var refreshInterval = 10000;   
   Liferay.Portlet.refresh(portletSelector);
   setInterval(refreshAssetPublisherPortlet, refreshInterval);
}
refreshAssetPublisherPortlet();

Calling Non-final Methods from Constructors

For more detail
http://www.informit.com/articles/article.aspx?p=20521