Валидация url

        function show_url_preview(url)
        {
            var objRE = /^(?:(?:https?|ftp|telnet):\/\/(?:[a-z0-9_-]{1,32}(?::[a-z0-9_-]{1,32})?@)?)?(?:(?:[a-z0-9-]{1,128}\.)+(?:com|net|org|mil|edu|arpa|ru|gov|biz|info|aero|inc|name|[a-z]{2})|(?!0)(?:(?!0[^.]|255)[0-9]{1,3}\.){3}(?!0|255)[0-9]{1,3})(?:\/[a-z0-9.,_@%&?+=\~\/-]*)?(?:#[^ \'\"&<>]*)?$/i;
            url= url.replace(/\s/g, '');
            return objRE.test(url);
        }