I am very new to VB6..I meet problem with my simple codes as follow:

Private Sub cmdTest_Click()
Dim mTotal as Double
Dim mVAT as Single
Dim mVATValue as Single

mTotal= 16,589.7138
mVAT=10

UpdateVAT mTotal, mVAT, mVATValue

' My problem goes here

Msgbox mVATValue ' Result = 1,658.97138 (This is the correct result)

' I want to display the result with to the text box with the following

format: ###,###,##0.0000

mDisplay = Format(mVATValue, "###,###,##0.0000")

But the result is: 1,658,9714 ==> the decimal digits was rounded automatically.. This is my problem .. I don't want to the result will NOT rounded automatically

End Sub


Private Sub UpdateVAT(ByVal pCurrentTotal As Double, ByVal pVAT As Single, ByRef pVATValue As Single)
Dim mVAT as Single
mVAT = pVAT / 100
pVATValue = mGTotal * mVAT
End Sub


Any suggestion or idea .. is highly appreciated and thanks in advance

Regards
Teddy