I use eclipse 3.0, it always notifies me "couldn't find the main class,program will exit".It seems all things stay on the last project, when i edit code, there is no reaction(e.x. highlights keyword).
did you click "run" in eclipse, and set up the main class, it has a search button or something as well to find it, maybe use that because it will only list classes that have a main method.
Is your project a Java Project? Did you set the Build Path correctly (especially the source path)?
The soul is dyed the color of its thoughts. Think only on those things that are in line with your principles and can bear the light of day. The content of your character is your choice. Day by day, what you do is who you become. Your integrity is your destiny - it is the light that guides your way. - Heraclitus