How to check if a tree node is dragged out of a tree

[mutouaa]

Hi all,

I am now trying to implement a small feature to drag a tree node out of treepanel to delete the node, so that I can remove the toolbar from tree panel.
my solution is to use enddrag listener, but I didn't find out how to check if the tree node is dragged out of the tree(only delete when dragged out). can anybody tell me how to check? or am I using the wrong listener? thanks.

my ascx file is simplified below:

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="CompositeConditionQueryControl.ascx.cs"
    Inherits="YTForever.Web.Host.Components.CompositeConditionQueryControl" %>
<%@ Register Assembly="Ext.Net" Namespace="Ext.Net" TagPrefix="ext" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Linq" %>
<script type="text/javascript">
    var removeNode = function (e, tree) {
        //if the node is dragged out of tree, remove it, else return false;
        var id;
        if (tree.getSelectionModel().getSelectedNode() != null)
            id = tree.getSelectionModel().getSelectedNode().id;
        else
            return false;
        DirectX.CompositeConditionQueryControl1.RemoveNode(id, {
            success: function (result) {
                var nodes = eval(result);
                if (nodes.length > 0) {
                    tree.initChildren(nodes);
                    tree.root.expand(true, true);
                }
                else {
                    tree.getRootNode().removeChildren();
                }
            }
        });
    };

</script>
<ext:TreePanel ID="TreePanel1" runat="server" Title="Query" AutoScroll="true" RootVisible="True"
    BodyStyle="padding-left:10px" Width="460px" Height="400px" EnableDrag="true">
    <Listeners>
        <EndDrag Handler="removeNode(e,#{TreePanel1});" />
    </Listeners>
</ext:TreePanel>