code: function pongTree_UpdateData( divId, paramObj ) {
  	log( "pongTree", "udateData "+divId );
  	var pmd = poTree[ divId ].config;
      if ( pmd.dataURL ) {
        log( "pongTree", 'calling '+pmd.dataURL);
        $.getJSON( 
          pmd.dataURL, 
          paramObj,
          function( treeDta ) {
            var treeHtml = "";
            if ( pmd.treeArray && treeDta[ pmd.treeArray ] ) {
              if ( pmd.titleField && treeDta[ pmd.titleField ] ) {
                treeHtml += '<div class="treeInfo">'+treeDta[ pmd.titleField ]+'</div>';
              }
              treeHtml += pongTree_getTree( divId, pmd, treeDta[ pmd.treeArray ], 0 );
              log( "pongTree", 'result: '+treeHtml);            
              $( '#'+divId+'pongTreeDiv' ).html( treeHtml );
              publishEvent( 'feedback', {'text':'Tree updated.'} );
            }
          }
        );                  
      }   
  	log( "pongTree", "end.");
  }
docs: update data call back hook