From Chris Nebel of Apple’s AppleScript Engineering group
ignoring application responses
tell application “loginwindow” to <
The double pointy brackets around the raw event call should be replaced by option-backslash and shift-option-backslash.The “rlgo” is short for “really log out”; if you want the “are you sure you want to log out” dialog, use aevtlogo instead. A future version of AppleScript will have a real command similar to “shut down”.