Nothing happens

[Saren]

Hey guys, so I wanted to try out the script where you pick up an item and a monster spawns.... yet it don't work even though I watched Your Computers tut on it... here's da script:
void OnStart()
{
SetEntityPlayerInteractCallback("Upperfloorkey", "ActivateMonster", true);
}


//Spawn Infected
void ActivateMonster(string &in item)
{
SetEntityActive("character_infected_1", true);
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_1", 2, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_2", 0, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_3", 0, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_4", 0, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_5", 0, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_6", 0, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_7", 0, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_8", 0, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_9", 0, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_10", 0, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_11", 0, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_12", 0, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_13", 0, "");
AddEnemyPatrolNode("character_infected_1", "PathNodeArea_14", 0, "");
}
void Despawncharacter_infected_1(string &in asParent , string &in asChild , int alState)
{
SetEntityActive("character_infected_1", false);
}

void OnLeave()
{
}