function button(sAction, sButtonType) {
			var sText;

			// Don't check in ResourceBundle library if the button is with custom text
			if (MessageBox.Action.hasOwnProperty(sAction)) {
				sText = MessageBox._rb.getText("MSGBOX_" + sAction);
			}

			var oButton = new Button({
				id: ElementMetadata.uid("mbox-btn-"),
				text: sText || sAction,
				type: sButtonType,
				press: function () {
					oResult = sAction;
					oDialog.close();
				}
			});
			return oButton;
		}
creates a button for the given action