Help - enable blank screen in remote computer

[<gui...@gm...>]

Hello

i hope someone help me.

i'm trying to enable blank screen in remote computer, for users that are in
remote computer don't see what i'm doing.
i've try it to go to the vnc server option, hide remote cursor, enable blank
screen and mouse lock.
but notting happens. it do always the same. it shows me what i'm doing in
the remote computer

Many thanks.

Guimenez