How to determine whether the user has switched to another tab of the current browser
<p>I wish to determine using jquery or javascript that is the user has switched tab standing on the same browser?</p>

<p>I.e. if the user is currently standing on browser say mozilla-firefox tab no.1 , now he has opened another tab say tab no.2 , at that point a popup should appear , with the message "tab changed"</p>
