Why do I get this error in php?
<p>I'm using the following code to loop through couple of links from my database, to check the header status of each one</p>

<pre><code>$con = mysql_connect("localhost","root","");
if (!$con)
{
    die('Could not connect: ' . mysql_error());
}
mysql_select_db("tracker", $con);

$result=mysql_query
        ("

        SELECT id,ziel_url FROM wm_mapping WHERE ziel_url LIKE '%websale7%'");

if (!$result)
{
    echo 'Could not run query: ' . mysql_error();
    exit;
}

$rows=array();
while ($row=mysql_fetch_assoc($result))
{
    $rows[] = $row;
}
$fp = fopen('url.csv', 'a+');
$csv=array();
foreach ($rows as $row){

        file_get_contents($row['ziel_url']);
        $response =$http_response_header[29];
        $csv[] = trim($row['id']).','.trim($row['ziel_url']).','.trim($response);


}
file_put_contents('url.csv', implode("\r\n", $csv), FILE_APPEND);
</code></pre>

<p>and for the line  <code>$response =$http_response_header[29];</code> i I get an error Undefined offset: </p>

<p>What does it mean?</p>
