BlueSense AppleScripts
How to disable Mac OS X session auto login in AppleScript
Disable the Mac OS X automatic login session and prompt for the password next time the computer will start.
script DisableAutomaticLogin
try
set my_password to getPassword(KeychainPasswordName)
set my_username to getUsername()
do shell script ("/usr/bin/defaults delete /Library/Preferences/com.apple.loginwindow.plist autoLoginUser") user name my_username password my_password with administrator privileges
on error errString number errorNumber
log (errString)
end try
end script