ext通过buttons的handler关闭window

一般打开一个window，再通过一个button关闭它，程序步骤如下：
1 定义一个window，并设置其id
2 button根据id获取window对象，并关闭
事例如下：
//窗口创建
window_c = function(object,name){
    new Ext.Window({
    title:"客户信息详细页",
id:"sky_window",
width:700,
autoHeight:true,
bodyStyle:{padding:"10px"},
items:[object],
buttons:[{
   text:name,
   handler:function(){
       var window1 = Ext.getCmp("sky_window");
                   if(name == "保存"){
                     var json ={kehuming:object.findById("kehuming").getValue(),
                              shenfenzheng:object.findById("shenfenzheng").getValue(),
                              kehubianhao:object.findById("kehubianhao").getValue(),
                              zhuangbiaodushu:object.findById("zhuangbiaodushu").getValue(),
                              lianxiren:object.findById("lianxiren").getValue(),
                              gudingdianhua:object.findById("gudingdianhua").getValue(),
                              louhao:object.findById("louhao").getValue(),
                              danyuanhao:object.findById("danyuanhao").getValue(),
                              fangjianhao:object.findById("fangjianhao").getValue(),
                              qibiaobianhao:object.findById("qibiaobianhao").getValue()};                    
                       var new_data = new cm_record(json);
                       grid.getStore().add(new_data);
                   };
                   if(name == "修改"){
                     var json ={kehuming:object.findById("kehuming").getValue(),
                              shenfenzheng:object.findById("shenfenzheng").getValue(),
                              kehubianhao:object.findById("kehubianhao").getValue(),
                              zhuangbiaodushu:object.findById("zhuangbiaodushu").getValue(),
                              lianxiren:object.findById("lianxiren").getValue(),
                              gudingdianhua:object.findById("gudingdianhua").getValue(),
                              louhao:object.findById("louhao").getValue(),
                              danyuanhao:object.findById("danyuanhao").getValue(),
                              fangjianhao:object.findById("fangjianhao").getValue(),
                              qibiaobianhao:object.findById("qibiaobianhao").getValue()};                    
                       var new_data = new cm_record(json);
                       var rsm = grid.getSelectionModel();
                       var store = grid.getStore();
                       var view = grid.getView();
                       for(var i=view.getRows().length-1;i>=0;i--){
                           if(rsm.isSelected(i)){
                               store.remove(store.getAt(i));
                               store.insert(i,new_data);
                           }
                       };
                       view.refresh();                    
                   };
   if(window1){
      window1.close();
   }}
        },{
               text:"取消",
               handler:function(window){
               var window1 = Ext.getCmp("sky_window");
               alert(window1.id);
   if(window1){
      window1.close();
   }}
       }]
    }).show(Ext.getBody());
};