How to set focus to a TLFTextfield object

I have been trying to understand why it will not work for me. Im working on the timeline in FLA开发者_运维知识库SH CS5.

According to this thread http://www.gotoandlearnforum.com/viewtopic.php?f=29&p=125498 you can try

txt.textFlow.interactionManager.setFocus();