主题：[求助]自动流转代码问题

在例程自动流转一DataColChanged中我增加了2列如下：

Select Case e.DataCol.Name
    Case "第一列","第二列","第三列","第四列","第五列","第六列","第七列","第八列"
        Dim dr As DataRow = e.DataRow
        Dim jd As String = "1A"
        If dr.IsNull("第一列") = False AndAlso dr.IsNull("第二列") = False Then
            jd = "1B"
            If dr.IsNull("第三列") = False AndAlso dr.IsNull("第四列") = False Then
                jd = "2B"
                If dr.IsNull("第五列") = False AndAlso dr.IsNull("第六列") = False Then
                    jd = "3B"
                    If dr.IsNull("第七列") = False AndAlso dr.IsNull("第八列") = False Then
                        jd = "4B"
                End If
            End If
        End If
        If jd = "1B" AndAlso dr("进度") = "2A" Then
        ElseIf jd = "2B" AndAlso dr("进度") = "3A" Then
        Else
            dr("进度") = jd
        End If
End Select

红色部分如何改写？因为对这4行代码不理解。