求教一个EXT.net下Treepanel的问题

 
<ext:DropDownField ID="d1" runat="server" Editable="false" Width="240" FieldLabel="<%$ Resources:lang,选择单位%>" EmptyText="<%$ Resources:lang,请至少选择一项 %>" Mode="ValueText">
                                                 <component>
                                                    <ext:TreePanel runat="server" ID="tr1" UseArrows="true" Animate="true" RootVisible="false" NoLeafIcon="true" AutoScroll="true" ContainerScroll="true" Height="200"
                                                        Shadow="None">
                                                    </ext:TreePanel>
                                                </component>
                                                 <Listeners>
                                                     <collapse handler="this.setValue(getValues(#{tr1}),getText(#{tr1}),false);" />
                                                     <Change Handler="s1.reload();select();" />
                                                 </Listeners>
                                             </ext:DropDownField>前台用来显示的控件 用ext:DropDownField 嵌套了ext:TreePanel
后台用 d1.SetValue(cookieUserInfo["value"].ToString(), HttpUtility.UrlDecode(cookieUserInfo["text"].ToString()));
这个进行了赋值问题是这个值只是付在ext:DropDownField 上了，可以用。
但是要从新选择的一些项的时候 我点开treepanel，这个控件默认是一个都没有选中的
求教怎么在getValues的时候同时也把Treepael也选中相应的项？