session_start();
$id = session_id();
$Time = time();
$oldTime = time();
$ar = @file('file.txt');
$n = 0;
for($i=0;$i<sizeof($mas); $i++)
{
$line = explode("/",$ar[$i]);
if($line[1]>$oldTime)
{
$new_ar[$n] = $ar[$i];
$n++;
}
}
for($i=0;$i<sizeof(new_ar);$i++)
{
$line = explode("/",$ar[$i]);
if($line[0] == $id)
{
$line[1] = trim($Time)."\n";
$is_id = true;

$line = implode("/",$line);
$new_ar[$i] = $line;

}
}
$fp = @fopen('file.txt',"w");
for($i=0;$i<sizeof($ar);$i++)
{
fputs($fp,$new_ar[$i]);
}
fclose($fp);
if(!$is_id)
{
$fp = @fopen('file.txt',"a");
$line = $id."/".$Time."\n";
fputs($fp,$line);
fclose($fp);
}
$ar1 = file('file.txt');
echo "Сейчас посетителей - ".$sizeof($ar1);