A better way to add Social Media scripts and any other external scripts

var scripts = {
   'facebook-jssdk': '//connect.facebook.net/en_US/all.js#xfbml=1',
   'googleplus'    : 'https://apis.google.com/js/plusone.js',
   'twitter-wjs'   : '//platform.twitter.com/widgets.js',
   'analytics'     : ('https:'==location.protocol?'//ssl':'//www') + '.google-analytics.com/ga.js'
 }, script, _gaq=[['_setAccount','UA-XXXXX-X'],['_trackPageview']];

 for (var id in scripts) {
   script = document.createElement('script'); script.src = scripts[id];
   script.id = id;script.type = 'text/javascript'; script.async = true;
   (document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(script);
 }

Don't forget to add <div id="fb-root"></div> to your markup when you're using Facebook.