Use the OSX Lion Lock feature on a Macbook Air Possible Duplicate:
  Is there a similarly fast alternative to Crtl + Shift + Eject for new Macbook Air?  




Is there a way to use the new Lock feature of OSX Lion on a Macbook Air which does not come with an Eject key?
You're not the first person to have this problem. The best workaround so far seems to involve Automator.
See: 
Is there a similarly fast alternative to Crtl + Shift + Eject for new Macbook that lack eject keys?