public static function req($id = NULL, $def = NULL, $c = true, $s = true, $l = C2_REQ_LENGTH)
{
$t = "_" . C2_REQ_TYPE;
global ${$t};
$v = (!isset(${$t}[$id]) or ${$t}[$id] == '') ? $def : ${$t}[$id];
if ($c) {
unset(${$t}[$id]);
}
if ($s && !empty($v)) {
$v = c2Str::trunc(c2Str::alnum($v), $l);
}
return $v;
}
