setcookie的相关疑问?

我的登录函数如下:
// ------------------------------ 登录函数 ------------------------------ //function login($username,$password){
require ("../config.php");
if($conn=OCILogon("$dbuser","$dbpasswd","$dbname"))
{
$tableb=OCIParse($conn,"select * from web.adminuser where name='$username'");
OCIDefineByName($tableb,"NAME",$name);
OCIDefineByName($tableb,"PASS",$pass);
OCIDefineByName($tableb,"GROUPID",$groupid);
OCIDefineByName($tableb,"KESHI",$keshi);
OCIExecute($tableb);
while(OCIFetch($tableb))
{
if ($username=="" || $password==""):
echo "用户名或密码不能为空";
echo "<META HTTP-EQUIV=REFRESH CONTENT='0;URL=index.php'>";
exit;
endif;if ($name == ""):
echo "用户名错误";
echo "<META HTTP-EQUIV=REFRESH CONTENT='0;URL=index.php'>";
exit;
endif;if ($password != $pass):
echo "密码错误";
echo"你输入的密码:$password<br>";
echo"用户表的密码:$pass<br>";
echo "<META HTTP-EQUIV=REFRESH CONTENT='0;URL=index.php'>";
exit;
endif;setcookie ($cookie_name."[1]",$username,time()+(1*24*3600));
setcookie ($cookie_name."[2]",$password,time()+(1*24*3600));
setcookie ($cookie_name."[3]",$groupid,time()+(1*24*3600));
setcookie ($cookie_name."[4]",$keshi,time()+(1*24*3600));
echo "登录成功!";
echo "<META HTTP-EQUIV=REFRESH CONTENT='0;URL=admin.php'>";exit;
}
OCILogoff($conn);
}
} // 结束登录函数我的退出函数如下:
// ------------------------------ 退出函数 ------------------------------ //
function logout(){
require ("../config.php");
setcookie ($cookie_name."[1]","");
setcookie ($cookie_name."[2]","");
setcookie ($cookie_name."[3]","");
setcookie ($cookie_name."[4]","");
echo "<a href=index.php>注销成功</a>";
echo "<META HTTP-EQUIV=REFRESH CONTENT='0;URL=index.php'>";
exit;
} // 退出函数结束我的验证是否登陆函数:
// ------------------------------ 验证函数 ------------------------------ //function islogin($username,$password){
require ("../config.php");
// 如果cookie[用户名/密码]为空, 跳转到登录页面
if ($username=="" || $password==""):
echo "<META HTTP-EQUIV=REFRESH CONTENT='0;URL=index.php'>";
exit;
endif;// 获得用户名下的密码
if($conn=OCILogon("$dbuser","$dbpasswd","$dbname"))
{
$tableb=OCIParse($conn,"SELECT * FROM web.adminuser WHERE name='$username'");
OCIDefineByName($tableb,"NAME",$name);
OCIDefineByName($tableb,"PASS",$pass);
OCIExecute($tableb);
while(OCIFetch($tableb))
{
// 如果cookie[密码]不正确, 跳转到登录页面
if ($pass != $password):
echo "<META HTTP-EQUIV=REFRESH CONTENT='0;URL=index.php'>";
exit;
endif;
}
OCILogoff($conn);
}
} // 结束验证函数回复：我又来问问题了!  
 相关页面的调用:
//验证是否登陆
islogin($HTTP_COOKIE_VARS[$cookie_name][1],$HTTP_COOKIE_VARS[$cookie_name][2]);
$cookie_user = $HTTP_COOKIE_VARS[$cookie_name][1];
// 退出
if ($action == "logout"):
logout();
exit;
endif;老大们,帮忙分析分析吧,谢谢了,第一次使用cookie,难免遇到问题!