title: Ext.Window show method open window behind current opened window in extjs 3.4
body: <p>I am not getting new window on current window after performing <strong>window.show()</strong> method.</p>
  
  <p>This JS code for <strong>current window</strong> :</p>
  
  <pre><code>stPopupWindow = new top.Ext.Window({
              title : title,
              id : 'stPopupWindowId', 
              x: 0,
              y: 0,
              width: screenWidth,
              height: screenHeight,
              draggable: false,modal:true,closeAction:'close',plain: true,
              layout:'fit',
              autoScroll:true,
              maximizable : true,
              minimizable : true,
              items:[...]});
  </code></pre>
  
  <p>This JS code for <strong>I am trying to open another window from current window</strong>. But It would open behind the current window. :</p>
  
  <pre><code>popupWindowFileUpload = new Ext.Window({ 
      title : "Upload Files", 
      id : 'popupWindowFileUploadId', 
      layout:'fit', 
      width:470,
      height:250,
      draggable: false,
      modal:true,
      closeAction: 'close',
      plain: true,
      maximizable : true,
      minimizable : true,
      items:[pnlFileUpload]
  });
  popupWindowFileUpload.show();
  </code></pre>
  
  <p><strong>Note :</strong> I can see that window after closing current window. 
  If you know something related to this problem than please tell me, Am I doing something wrong?</p>