code: function button(sAction) {
  				var sText = rb && rb.getText("MSGBOX_" + sAction),
  					oButton = new Button({
  						id: sDialogId + "--btn-" + sAction,
  						text: sText || sAction,
  						press: function () {
  							oResult = sAction;
  							oDialog.close();
  						}
  					});
  				if (sAction === oDefaultAction) {
  					oDefaultButton = oButton;
  				}
  				return oButton;
  			}
docs: creates a button for the given action