How to get the node data in the TreePanel?

I want to get the node data in the TreePanel when the checkbox of the node change, my code as:
_{var loadOperation = function (pageId, node) {}

_{App.direct.LoadOperation(pageId, '');}
_}

_{var nodecheckchange = function (check) {}
_{App.direct.NodeCheckChange('',check);}
_}

_{<ext:TreePanel runat="server" ID="treeView_modules" RootVisible="false">}
_<Listeners>
_{<ItemClick Handler="if (record.data.Page_ID) { loadOperation(record.data.Page_ID, node); return false;}" StopEvent="true" Delay="500" />}
_{<CheckChange Handler="nodecheckchange(checked);" StopEvent="true" Delay="500">}
_{</CheckChange>}
_</Listeners>
_{</ext:TreePanel>}the node build as following:
_{foreach(var n in allQ.Where(item=>item.Parent_ID==m.PageID))}
_{
_{Node child = new Node();}
_{child.Text = n.PageName;}
_{child.IconFile = n.PageIcon;}
_{child.NodeID = BaseControl.GenerateID();}
_{child.CustomAttributes.Add(new ConfigItem("Page_ID", n.PageID));}
_{child.Leaf = true;}
_{child.Checked = n.IsCheck;}
_{node.Children.Add(child);}
_}How can i get the Page_ID value in the codebehinde when the checkbox change?