Are you talking about code to create in your application a soft return or something in the actual IDE?
Since you specified Flex Builder, I'll assume you meant the IDE. As far as I knew the enter key will create a new line. Whether that sends a line feed, or carriage return, or both was dependent upon operating system.
If I understand correctly, Windows OS uses both Carriage Return and Line Feed. I thought the MAC OS used only Line Feed. If you're using Microsoft Word on Windows you can do a 'hard' return using the enter key, or a soft return using the control Enter. This does not appear to carry over the Eclipse / Flex Builder, though. And even if it did, I'm not sure why it would matter. The important thing is that you're able to separate your code to multiple lines, right?
Yes I meant to say the IDE. Yes, the simple enter will do. Thanks!