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