Get real width of window. The same as CSS media query.

.js

	function viewport() {
		var e = window, a = 'inner';
		if (!('innerWidth' in window )) {
			a = 'client';
			e = document.documentElement || document.body;
		}
		//return { width : e[ a+'Width' ] , height : e[ a+'Height' ] };
		return e[ a+'Width' ];
	}