Sound problem

[Lizard]

I just started a new map. where there is a leak that i got to work perfectly with ps and everything, the only thing that wont work is the sound, and i have no idea why

//First time entering map
///////////////////////////
void OnStart()
{

}

//When entering map
////////////////////////
void OnEnter()
{
PlaySoundAtEntity("WaterFlow", "12_epoxy_flow.snt", "WaterStreamArea", 0.1f, true);
}

//When Leaving map
///////////////////////
void OnLeave()
{

}

And yes, the entity to play the sound at is spelled correctly.