php alert 简易安全验证登录

$user = 'asd';
$pass = '123';

if(isset($_SERVER['PHP_AUTH_USER']) && ($_SERVER["PHP_AUTH_USER"]==$user && $_SERVER["PHP_AUTH_PW"]==$pass)){
//echo "<p>{$_SERVER['PHP_AUTH_USER']}</p>";
} else {
header("WWW-Authenticate: Basic realm=\"test1\"");
header("HTTP/1.0 401 Unauthorized - test");
echo "<p>please try again</p>";
exit;
}