I want to ajax update javascript script using with primefaces.
 
        put it in a JSF tag, and give it Id.
<h:panelGroup id="myScript">
   <script type="text/javascript">
     function lineChartExtender(){
         this.cfg.highlighter = {
             showTooltip: true,
             tooltipAxes: 'both',
             tooltipLocation: 'n'
        };
         this.cfg.seriesDefaults = {
                 showMarker: #{query.stringMarker}
         };
      }       
    </script>
</h:panelGroup>
and have a button or link that does some action, or not, and updates this <h:panelGroup>
<h:commandLink action="#{myBean.doSomething}" update="myScript"/>