Monster doesn't spawn when "Script" area has collided with player (on custom story)

[ryuthebeardy]

Recently, I have decided to make a custom story however I am new to the whole "C++" coding. So i kinda need help on this code below.
void OnStart()
{
AddEntityCollideCallback("Player", "PlayerCollide", "MonsterFunction", true, 1);
}
void MonsterFunction(string &in asParent, string &in asChild, int alState)
{
SetEntityActive("servant_grunt_1", true);
AddEnemyPatrolNode("servant_gsrunt_1", "PathNodeArea_1", 2, "");
AddEnemyPatrolNode("servant_grunt_1", "PathNodeArea_2", 0, "");
AddEnemyPatrolNode("servant_grunt_1", "PathNodeArea_3", 0, "");
AddEnemyPatrolNode("servant_grunt_1", "PathNodeArea_4", 0, "");
AddEnemyPatrolNode("servant_grunt_1", "PathNodeArea_5", 0, "");
}
void OnEnter
{

}
void OnLeave
{

}
Here is what I have done (If my description is confusing, i have a image of the area of my level),

  wtf.jpg (Size: 218.03 KB / Downloads: 127)
I have placed a monster behind a door (he is inactive), and when the player crosses the door, he should collide with the "Script area" named "PlayerCollide", in which should active the monster, however doesn't... Can anyone help?