tab key press 2

var firstElement = Ext.getCmp('user');
var lastElement = Ext.getCmp('password');
Ext.EventManager.addListener(
  firstElement.el,
  'keydown',
  function(e){
    var key = e.getKey();
    var shiftKey = e.shiftKey;
    if (shiftKey && key == e.TAB){
      e.stopEvent();
      lastElement.focus(true, 100);
    }
  }
);

Ext.EventManager.addListener(
  lastElement.el,
  'keydown',
  function(e){
    var key = e.getKey();
    var shiftKey = e.shiftKey;
    if (!shiftKey && key == e.TAB){
      e.stopEvent();
      firstElement.focus(true, 100);
    }
  }
);