Project - view as: Packages - listing all types of files - how to restrict?

hi,
I'm sure this is a very simple question, but just can't see how to do it.  In the project window, I have view as : Packages set. This shows me my source files, but it is also listing files I don't want to see, .LCK* files and backup files with Filename.java~

How can i remove these files from the packages view?

Thanks,
Mark.