Real-time views count- logging to a .txt in a user folder - php

Question

I've got this code that logs to a .txt file in a user folder. I need it to refresh in real time or 1 or 5 seconds.
The code basically logs a visitor that viewing the page, so it will say: Viewers: 1 and when the visitor exit the page it will go back to Viewers: 0
The script is working but I want it to refresh.
Any ideas?
Here the PHP Code:
require_once 'dbconfig.php';
if ($_GET[user] != ""){
$check_query = mysql_query("SELECT * FROM profiles WHERE username='$lowerusername'");
while ($display = mysql_fetch_array($check_query)) {
$username = $display['username'];
}}
$dataFile = "profile/$username/visitors.txt";
$sessionTime = 1; //this is the time in **minutes** to consider someone online before removing them from our file
//Please do not edit bellow this line
error_reporting(E_ERROR | E_PARSE);
if(!file_exists($dataFile)) {
$fp = fopen($dataFile, "w+");
fclose($fp);
}
$ip = $_SERVER['REMOTE_ADDR'];
$users = array();
$onusers = array();
//getting
$fp = fopen($dataFile, "r");
flock($fp, LOCK_SH);
while(!feof($fp)) {
$users[] = rtrim(fgets($fp, 32));
}
flock($fp, LOCK_UN);
fclose($fp);
//cleaning
$x = 0;
$alreadyIn = FALSE;
foreach($users as $key => $data) {
list( , $lastvisit) = explode("|", $data);
if(time() - $lastvisit >= $sessionTime * 10) {
$users[$x] = "";
} else {
if(strpos($data, $ip) !== FALSE) {
$alreadyIn = TRUE;
$users[$x] = "$ip|" . time(); //updating
}
}
$x++;
}
if($alreadyIn == FALSE) {
$users[] = "$ip|" . time();
}
//writing
$fp = fopen($dataFile, "w+");
flock($fp, LOCK_EX);
$i = 0;
foreach($users as $single) {
if($single != "") {
fwrite($fp, $single . "\r\n");
$i++;
}
}
flock($fp, LOCK_UN);
fclose($fp);
if($uo_keepquiet != TRUE) {
echo '<strong>Viewers:</strong> ' . $i . '';
}