Soldato
whats the keystroke command to lock my macbook air??
Applications > Utilities > Keychain Access > Preferences > Show status in menu bar
That will put a padlock in your menu bar that you can click and then lock the screen.
I don't think there's a simple key combination shortcut like on Windows.
There is a sleep display shortcut but it wouldn't work on MBA, as one of the keys is "eject'.
Look for an preferences plugin called LockTight. It only does one thing, allowing you to assign a keyboard combination to lock the current user.