Mixing chemicals problem !

[Selyp]

My script is

void OnGameStart()
{
AddCombineCallback("", "Vinegar", "PhosphoricAcid", "CombineFunc", true);
}
void CombineFunc(string &in asItemA,string &in asItemB)
{
SetMessage ("Descriptions", "Piano", 10);
GiveSanityBoost();
RemoveItem("Vinegar");
RemoveItem("PhosphoricAcid");
GiveItem("", bucket_of_tar", "bucket_of_tar", "bucket_of_tar.tga", 1);
}

The message is just there so I can determine if the function is being called. Since it's not showing up I'm assuming that the function is being called at all, which is strange because I am positive the names of the items are correct. I have triple checked them multiple times lol.