Private Sub txtCodiceBarre_TextChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtCodiceBarre.TextChanged
        Dim str, str1, str2, str3 As String
        Dim i, len1, len2, lenCon1, lenCon2 As Integer
        str = txtCodiceBarre.Text
        vNum = Len(str)

        If vNum = 8 Then
            str = txtCodiceBarre.Text
            EAN8.Text = str
            len1 = Len(str)
        End If

        If vNum = 13 Then
            str1 = txtCodiceBarre.Text
            EAN13.Text = str
            len2 = Len(str1)
        End If

        str2 = EAN8.Text
        str3 = EAN13.Text
        lenCon1 = Len(str2)
        lenCon2 = Len(str3)

        If lenCon1 = 8 And lenCon2 = 13 Then
            txtQuantita.Focus()
        End If
    End Sub