change dvar when exit the server

i made that thing:
[PHP]onPlayerSpawned()
{
self endon("disconnect");

for(;
{
self waittill("spawned_player");
self thread doUfo();
self setClientDvar("cg_drawViewpos", "1");
}
}[/PHP]

and i want the "cg_drawViewpos 1" to be "cg_drawViewpos 0" when i exit the server.
how can i do that?

and

its aint working

someone???