Command for updating or refreshing desktop menu

[jupiter]

Hi,

Is there any command which can be used to updating or refreshing desktop menu?
When I install my applications which were added to xfce desktop menu
on CentOS 6.2, showing the application icon on menu were not
immediately, sometime I have to close the desktop and start it again
to see new icons showing on the menu. Not clear if there was cache to
hold the update or if I need to run some commands to force the menu
update to be effected immediately. Appreciate any helps.

Thank you.

Kind regards.

Jupiter