Mouse Over a Control/Grid

[omlac]

I have been trying to add a javascript function to display information when there is a moveover a grid, and i want the message to disapear on its own after a (reasonably)short time, say a message that just say "use ctr + shift to select multi rows", but i cant seem to find this info, does anyone know how to do it or where to find info on how to do it.