preg_match(): Unknown modifier '/'

When i give this regular expression for validating URL it shows error...

preg_match(): Unknown modifier '/' in C:\wamp64\www\php\Form Validation\form.php on line 36

if(!preg_match("/%^(?:(?:https?|ftp)://)(?:\S+(?::\S*)?@|\d{1,3}(?:\.\d{1,3}){3}|(?:(?:[a-z\d\x{00a1}-\x{ffff}]+-?)*[a-z\d\x{00a1}-\x{ffff}]+)(?:\.(?:[a-z\d\x{00a1}-\x{ffff}]+-?)*[a-z\d\x{00a1}-\x{ffff}]+)*(?:\.[a-z\x{00a1}-\x{ffff}]{2,6}))(?::\d+)?(?:[^\s]*)?$%iu/",$website)){
            $websiteerror="Invalid URL";