To create portlet URL using javascript,use below script :
<script>
function createRowURL( row ) {
var portletURL = new Liferay.PortletURL();
portletURL.setParameter("rowNumber", row );
return portletURL.toString();
}
OR
<script>
function createRowURL( row ) {
var portletURL = new Liferay.PortletURL();
portletURL.setParameter("rowNumber", row );
return portletURL.toString();
}
OR