<?php
$NUMBER;

# retrieve counter if file exists
if(file_exists("hits.txt"))
{
    $FILE = fopen("hits.txt","r");
    if($NUMBER = fgets($FILE,999))
    { $NUMBER = trim($NUMBER); }
    fclose($FILE);
}

$FILE = fopen("hits.txt","w");
$NUMBER=$NUMBER + 1;
fwrite($FILE,$NUMBER);
fclose($FILE);

echo "<p>" . $NUMBER . "</p>";
?>