code: function(direction, cloud_element) {
    var start = $( '#cloudGraphPagingStart' ).val();
    var rows = $( '#cloudGraphPagingRows' ).val();
    var startAt = start ? parseInt(start) : 0;
    var numRows = rows ? parseInt(rows) : 20;
    var newStart = Math.max(startAt + (rows * direction),0); 
    $( '#cloudGraphPagingStart' ).val(newStart);
    
    var graph_element = $( '#graph-content', cloud_element );
    $( '#canvas', graph_element).empty();
    init_graph( graph_element );  
  }
docs: updates the starting position for paged navigation and then rebuilds the graph based on the selected page