I just realized that my website Google +1 button is not working. So, I checked Google +1 codes in my website and found nothing missing.
what is Google +1 button
Actually Google has updated code you need to integrate in your website to show Google +1 button. Earlier they had an external plusone.js file. But now no external file is required.
New method is little different. Visit below link to get new code for Google Plus one button.
[url]Google +1 button for webmaster[/url]