主题：请问这段代码 哪里错误

Dim db_bm As WinForm.DropDownBox = e.Form.Controls("DropBox1")
Dim dt_sj As WinForm.DateTimePicker = e.Form.Controls("DateTimePicker1")

If CurrentTable.Current.DataRow.RowState = DataRowState.Added OrElse CurrentTable.Current.DataRow.RowState = DataRowState.Modified Then
    If db_bm.DropDownBox = "" Then
        MessageBox.Show("请填写"部门"数据")
    End If
    If dt_sj.DateTimePicker = "" Then
        MessageBox.Show("请填写"日期"数据")
    End If
End If