var node = $('#tt').tree('find', 12); //find a node$(node.target).draggable('disable');$(node.target).draggable('enable');
$('#tt').tree({ dnd: true, onDragOver: function(target, source){ var cc = $(this).tree('getChildren',target); for(var i=0; i<cc.length; i++){ if (cc[i].target == source.target){return false} // return false to deny drop, restrict the node to move away from it parent } }});