Extjs4 remove the close button (similar to Ext. Msg. alert) _ extjs

Similar to Ext. msg. alert (); but no close button. Because the close button in the Extjs4 message box does not execute the callback function, click Close to close the window, next we will introduce in detail how to remove the close button, similar to Ext. msg. alert (); but no close button

Because the close button in the Extjs4 message box does not execute the callback function, click the close button to close the window.
The implementation code is as follows::

The Code is as follows:

Ext. Msg. show ({
Title: 'System prompt ',
Msg: 'close button in the upper right corner of the Extjs4 removal prompt box ',
Buttons: Ext. Msg. OK,
Fn: showResult,
Closable: false
});