The version of NetBeans that I use is 6.5.1
Install http://plugins.netbeans.org/plugin/36810/show-and-change-line-endings in netbean and it will show the line break in bottom right task bar inside netbean also you can switch between Windows, Linux and Mac.
recently updated to 7.2 and started to search for the solution I had at 7.1.2 version. Take a look at this plugin that helps to switch between line endings types.
I think you can't. NB will use the native OS format where it is running. If you have issues with that, there is an Ant FixCRLF task.