changing\hiding mouse cursor over plugin

Hi,
I'm developing a plugin for FF/Chrome/IE/Gecko.
Within my plugin i need to change or hide the mouse cursor.
The plugin is windowless (and should remain so).

I have tired changing the style of DOM containing the plugin but it
does not work, as does calling SetCursor/ShowCursor (probably because
of the Sand Boxing).

I know this is technically possible ( Adobe Flash is able to change
mouse cursor, I.E YouTube flash player)

Thanks,
Koby