void main()
{
    object oChosenTrap = GetLocalObject(OBJECT_SELF, "TRAP4");

    SetLocalObject(OBJECT_SELF, "TRAP_TO_SET", oChosenTrap);

    // Figuring out the base trap number is a bit tricky...
    string sTagR2 = GetStringRight(GetTag(oChosenTrap), 2);
    int nTagR2 = StringToInt(sTagR2);
    nTagR2 --;
    // Switching acid splash and negative trap numbers
    switch (nTagR2)
    {
        case 32:
        case 33:
        case 34:
        case 35:
        nTagR2 = nTagR2 + 8;
            break;
        case 40:
        case 41:
        case 42:
        case 43:
        nTagR2 = nTagR2 - 8;
            break;
    }
    SetLocalInt(OBJECT_SELF, "TRAP_BASE_NUMBER", nTagR2);
}