jquery - check database value every second - php

Question

I am having problems with a jquery. The code below is not triggered when the php page loads. I attempt to check the value of a field in a database table and do a redirect if the returned value is 0. I have been struggeling with this for hours and I have really searched around to find the answer. Any help is appreciated.
<script type="text/javascript">
$jQn(document).ready(function(){
var do_checking;
var status = 1;
var ui = "";
if(status == 1){
$jQn.blockUI.defaults.overlayCSS.opacity=.3;
$jQn.blockUI({
message: ui,
css: {
border: '10px solid #888',
backgroundColor: '#000',
'-webkit-border-radius': '10px',
'-moz-border-radius': '10px',
color: '#fff',
width: '50%',
left: '25%',
cursor: 'wait',
'-ms-filter': 'progid:DXImageTransform.Microsoft.Alpha(Opacity=10)',
'filter': 'progid:DXImageTransform.Microsoft.Alpha(Opacity=10)',
'-moz-opacity':.10,
opacity:.10,
padding:'15px'
}
});
do_checking = setInterval(check_search_status, 1000);
} else {
document.location = 'https://mysite.com/result.php';
}
});
function check_search_status(){
$jQn.ajax({
type: 'POST',
url: 'https://mysite.com/checksearchstatus.php',
data: {
id: '$owner'
},
dataType: 'json',
success: function(response){
if(response.status == 0){
clearInterval(do_checking);
document.location = 'https://mysite.com/result.php';
}
}
});
}
</script>
Here is the code of the separated php file
$con = mysql_connect($db_host,$db_username,$db_password);
if (!$con)
{
die('Feil ved tilkobling av: ' . mysql_error());
}
mysql_select_db($db_name, $con);
$response = array('status' => '');
$user_id = $_POST['id'];
// Build SQL
$first_search_sql = "SELECT `firstsearch` FROM `class_users` WHERE id = '".$user_id."'";
$first_search_result = $db->query($first_search_sql);
// Fetch result
$first_search_row = $first_search_result->fetch();
// Free result
$first_search_result->freeResult();
$response['status'] = $first_search_row['firstsearch'] ;
echo json_encode($response);