Ok, now look under your project the 'Debug Configurations' window, in tab
'Debugger'. See if there is a debugger declared. Then you should compile
your project using 'Debug' configuration (no optimization). In order to
actually debug, you need to be in debug perspective. If Eclipse does not
show this perspective when you give the debug command, you can open it
manually from the 'Window/Open Perspective/Other' menu item.