Window in extjs problem in reopening ( a unique and basic problem of extjs )

I had a problem ,widow ones closed is not opening due to items

extjs desktop system i created shortcut on the destop and when i click on the link first time window opens is working and if i close the subwindow and click on the same link again not opening not working

/*****this is the code till now *******/

Ext.Window{
  /**** here is my stuff ******/
  items:[ a1 ]
}

var a1 =  new Ext.FormPanel({ //*** other stuff ****// 
  items:[ new combobox({id:'com'})]
});
 /*****End of code till now *******/

if i change to

Ext.Window{
  /***** here is my 开发者_运维百科stuff ******/
  items:[ new  a1() ]
}

var a1 = Ext.extend( Ext.FormPanel ,{   
  /****some stuff ****/  
  items:[ new combo_box({id:'com'})]
} );

the combo_box does not work can somebody help me a little on this stuff

You need to destroy window items, before you destroy the window itself.

Altenratively, don't use global id;s for components that will be recreated several times. Consider using Ext.id() function to generate unique ids with given prefix.

items:[ new combobox({id:Ext.id()})]

If the form/combo isn't being modified each time you open the window, just add closeAction: 'hide' to your Window configuration. Then, the window will not be destroyed when you close it and you can call Window.show() to make it appear again.