Simple website hit counter (PHP version)

<?php

main();

function main() {

$data = "";
access_file("hit_count.txt", $data);

for ($n = 0; $n < strlen($data); $n++) {
$count[$n] = substr($data, $n, 1);
}

for ($n = 0; $n < 4 - strlen($data); $n++) {
echo "<img src=\"0tile.gif\" alt=\"0\">";
}

for ($n = 0; $n < strlen($data); $n++) {
switch ($count[$n]) {
case 0:
$insert = "0";
break;
case 1:
$insert = "1";
break;
case 2:
$insert = "2";
break;
case 3:
$insert = "3";
break;
case 4:
$insert = "4";
break;
case 5:
$insert = "5";
break;
case 6:
$insert = "6";
break;
case 7:
$insert = "7";
break;
case 8:
$insert = "8";
break;
case 9:
$insert = "9";
break;
default:
$insert = "0";
}
echo "<img src=\"" . $insert . "tile.gif\" alt=\"$insert\">";

}

}

function access_file ($filename, &$data) {
$file1 = fopen($filename, "r+") or die ("Unable to open file $filename for read / write.");
$data = fread($file1, filesize($filename));
$new_data = $data + 1;
fseek($file1, 0, SEEK_SET);
fwrite($file1, $new_data);
fclose($file1);

}


?>