登录验证成功后如何添加COOIE？？？？？

1. <?php
   
2. //error_reporting(0);
   
3. header("content-Type: text/html; charset=gbk");
   
4. include("cooon.php");
   
5. 
   
6. 
   
7. $password = $_POST['password'];
   
8. $username = $_POST['username'];
   
9. 
   
10. $q = "SELECT * from lyuc_members where username='$username'";
    
11. $xm=mysql_query($q);
    
12. $rs=mysql_fetch_array($xm);
    
13. $salt=$rs[salt];
    
14. $pwd=md5(md5($password).$salt);
    
15. if($pwd==$rs[password]){
    
16. 
    
17. //这里如何添加COOKIE?
    
18. echo "<script>alert('登录完成，返回首页!');location.href='dlsu.php';</script>";
    
19. }else{
    
20. echo "<script>alert('错误!');location.href='abc.php';</script>";
    
21. }
    
22. 
    
23. ?>

复制代码

登录成功后如何添加COOKIE才能使全站都访问到该COOKIE?

求高手指点？？？？？？？？？？？？？？？？？

没人回答啊，急用