Combining drills?

[Streetboat]

from my inventory.hps:

if (GetGlobalVarInt("DrillParts") == 3)
{
AddCombineCallback("", "drill_bit", "drill_handle", "CombineDrill", true);
AddCombineCallback("", "drill_bit", "drill_part", "CombineDrill", true);
AddCombineCallback("", "drill_part", "drill_handle", "CombineDrill", true);
}
if (GetGlobalVarInt("DrillPartsPlastic") == 3)
{
AddCombineCallback("", "drill_bit_plastic", "drill_handle_plastic", "CombineDrillToy", true);
AddCombineCallback("", "drill_bit_plastic", "drill_part_plastic", "CombineDrillToy", true);
AddCombineCallback("", "drill_part_plastic", "drill_handle_plastic", "CombineDrillToy", true);
}
void CombineDrill(string &in asItemA, string &in asItemB)
{
if(GetGlobalVarInt("DrillParts") != 3){
SetInventoryMessage("Inventory", "CombineDrillError", -1);
return;
}

PlayGuiSound("12_make_drill", 1.0f);

RemoveItem("drill_bit");
RemoveItem("drill_part");
RemoveItem("drill_handle");

GiveItem("hand_drill_1", "hand_drill", "handdrill", "hand_drill.tga", 0);
SetMessage("Inventory", "MadeDrill", 0);
}
void CombineDrillPlastic(string &in asItemA, string &in asItemB)
{
if(GetGlobalVarInt("DrillPartsPlastic") != 3){
SetInventoryMessage("Inventory", "CombineDrillError", -1);
return;
}

PlayGuiSound("12_make_drill", 1.0f);

RemoveItem("drill_bit_plastic");
RemoveItem("drill_part_plastic");
RemoveItem("drill_handle_plastic");

GiveItem("hand_drill_plastic", "hand_drill", "handdrillplastic", "hand_drill.tga", 0);
SetMessage("Inventory", "MadeDrill", 0);
}