I want to use the following check sum routine to check for the validity of
newly input medical record numbers (MRN). Problem is that some of the MRN's
have leading zero's so the routine won't work. If I change the MRN field to a
txt field, then it doesn't work at all.

Is there anyway to tell access not to cut off the zero's? Thanks for your
help. Robert

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Private Sub MRN_BeforeUpdate(Cancel As Integer)
If Len(MRN) <> 8 Then
   MsgBox ("Please enter the full 8 digit Medical Record Number")
Else
   If Len(MRN) = 8 Then
       Dim MR(8), I, J, K, L, Odd, Even As Integer
       For I = 1 To 8
           MR(I) = Val(Mid(MRN, I, 1))
       Next I
       Even = MR(2) + MR(4) + MR(6)
       Odd = 2 * (Val(Str(MR(1)) & Str(MR(3)) & Str(MR(5)) & Str(MR(7))))
       J = Len(Str(Odd))
       For I = 1 To J
           K = K + Val(Mid(Str(Odd), I, 1))
       Next I
       K = K + Even
       L = 10 * (Int(K / 10) + 1)
       If MR(8) <> L - K Then
           If L - K <> 10 Then MsgBox ("That Medical Record Number is NOT
valid!")
       End If
   Else
       MsgBox ("Please enter the full 8 digit Medical Record Number")
   End If
End If

End Sub
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