For Each number In InputTextBox.Lines
            If Not IsNumeric(number) And Val(number) < 0 Then
                MsgBox("ERROR " & vbNewLine & number & " value not accepted", , "Error Box")
                Return
            End If
        Next
        For i As Integer = 0 To InputTextBox.Lines.Count - 1
            output(i) = InputTextBox.Lines(i) / 39.37
        Next