center a Ext.Button in a panel

Hi,



I'm having problem trying to center a button in a panel.



If I don't set the width for the button, the button has all the page width. If I fix the width, the button is align left. I want to center the button in my panel.Change the layout of the panel to pack:'center' or change the style property of the button has not had success



Any solution ?



Best Regards,

Manolo Q.