Public Function IsInteger(ByVal Value As String) As Boolean
If Value Is Nothing OrElse _
Value.Length < 1 OrElse _
Value.Length > 11 OrElse _
Value.IndexOf("-") > 0 _
Then Return False
Dim iASC As Integer
For Each c As Char In Value
iASC = Asc(c)
If (iASC < 48 OrElse iASC > 57) AndAlso iASC <> 45 Then Return False
Next
Return True
End Function