Bit of an issue with my script

[A Tricky Carnie]

There seems to be a problem with my script that when I enter the map it gives me this error:

(1,1): ERR: No matching signatures to 'OnGameStart()' main (29,2): ERR : Unexpected end of file

Now I've never seen the 'OnGameStart(),' so I replaced my 'OnStart()' line to 'OnGameStart().' So now my script looks like this:

////////////////////////////
// Run when entering map
void OnGameStart()
{
SetEntityConnectionStateChangeCallback("lever_small01_1", "SecretDoor");
AddUseItemCallback("", "key_torture_chamber_1", "castle_2", "KeyOnDoor", true);
}

void KeyOnDoor(string &in asItem, string &in asEntity)
{
SetSwingDoorLocked("castle_2", false, true);
PlaySoundAtEntity("", "unlock_door", "castle_2", 0, false);
RemoveItem("key_torture_chamber_1");
}

void SecretDoor(string &in asEntity, int alState)
{
if (alState == -1)
{
SetMoveObjectState("castle_portcullis_1",1.0f);
PlaySoundAtEntity("", "quest_completed.snt", "close_gate", 0, false);
return;
}
}

////////////////////////////
// Run when leaving map
void OnLeave()
{

However I'm still getting the same error and I have no idea what to do. If anyone knows what to do the help would be appreciated. Also I did do a search on "OnGameStart()' on the wiki and didn't find anything but like I said, if anyone could point me in the right direction it'd be appreciated.