problem on php login file

[ramanagosu]

Hi
any one help me

logincheck.php
----------------------

<? 
    if($cookie_user_id=='') {
        $page = "index.php";
        header("Location: $page");    
    }
?>

i am using this file in another php file using following code
<? include("logincheck.inc"); ?>
i got following error
Undefined variable: cookie_user_id .
Cannot modify header information - headers already sent by

[Markus]

Where is $cookie_user_id pointing to? You can't access a variable that hasn't been defined. Use isset() to check if a variable exists. As for the header error, I'm guessing you've sent output to the browser in the parent file. Consider the following:

echo "Hello";
header( "Location: http://example/" );
 

This would produce an error because on line 1, you sent output to the browser (that is, when you send output, you send headers, too). Ergo, the header() method cannot resend the headers, so you end up with an error.

You could use the ob_* functions to buffer the output.