I am programming a simulator for 8051,i have some problem about the flag Altering in ADD and ADDC

'Is this Correct ?
CY, AC, OV, are function names that set the flags

For Calculating ADD we can call "ADD8(OP1,OP2)"
For Calculating ADDC we can call "ADD8(OP1,OP2,Carry)"

Public Function ADD8(ByVal Op1 As Byte, ByVal Op2 As Byte, Optional ByVal Op3 As Byte = 0) As Byte
Dim i As Integer
i = CInt(Op1) + CInt(Op2) + CInt(Op3)

ADD8 = LOW8(i)

AC (LOW4(Op1) + LOW4(Op2) + Op3) > 15

If i > 255 Then
CY True
If i < 0 Then
OV True
Else
OV False
End If
Else
OV False
CY False
End If

End Function