wtf.js

wtf.js

  if (
    (function(){
      var el = document.createElement('div'),
          bs = 'backgroundSize',
          ubs = bs.charAt(0).toUpperCase() + bs.substr(1),
          props = [bs, 'Webkit' + ubs, 'Moz' + ubs, 'O' + ubs];

      for ( var i in props ) {
        if ( el.style[props[i]] !== undefined ) {
          return true;
        }
      }

      return false;
    }())
  ) {
    return;
  };