code: function css(el, styles) {
  	if (isIE) {
  		if (styles && styles.opacity !== UNDEFINED) {
  			styles.filter = 'alpha(opacity=' + (styles.opacity * 100) + ')';
  		}
  	}
  	extend(el.style, styles);
  }
docs: Set CSS on a given element
  @param {Object} el
  @param {Object} styles Style object with camel case property names