A cookie is set using the
setcookie() function. Since cookies are part of the HTTP header, you must set any cookies before sending any output to the browser.
setcookie("user", "Tom", time() + 86400, "/"); // check syntax for function params
A created or modified cookie can only be accessed on subsequent requests (where
domainmatches) as the superglobal
$_COOKIEis not populated with the new data immediately.