title: Can 'update' attribute update two components simultanously?
body: <p>I have a question. Is that possible to update two components at a time?
  I am trying a code like this:</p>
  
  <pre><code>&lt;h:panelGroup id="pickList"&gt;
      &lt;p:panel  rendered="#{customCalender.visible}" widgetVar="searchTableBox"&gt;
  
      //Some codes.....
  
          &lt;p:commandButton value="Cancel" update="pickList" actionListener="#{customCalender.closeList}" style="background:#25A6E1;color:red;font-family:'Helvetica Neue',sans-serif;font-size:10px;border-radius:4px;" /&gt;
          &lt;p:commandButton value="Save" update="custDataTablePanel" actionListener="#{customCalender.saveTargetList}" style="background:#25A6E1;color:red;font-family:'Helvetica Neue',sans-serif;font-size:10px;border-radius:4px;"/&gt;
     &lt;/p:panel&gt;
  &lt;/h:panelGroup&gt;
  ....
  .....
  &lt;h:panelGroup  id="custDataTablePanel"&gt;
     &lt;p:panel rendered="#{customCalender.dataTableVisible}"&gt;
  ..
  ..
     &lt;/p:panel&gt;
  &lt;/h:panelGroup&gt;
  </code></pre>
  
  <p>Now I want when I click on the <code>Save</code> button it hides the <code>&lt;h:panelGroup id="pickList"&gt;</code> and displays the <code>&lt;h:panelGroup id="custDataTablePanel"&gt;</code> so I have two boolean values to control their visibility. but I need to update two of these panels. One I did with <code>update="custDataTablePanel"</code> it displays the data table after the button click.(in the method <code>saveTargetList</code> I updated the visibility of the <code>custDataTablePanel</code> to true.) but cant manage to hide the panel <code>pickList</code>.</p>
  
  <p>So I was wandering is there any way to hide and show these two panels in one button click.
  Please suggest.</p>