Query string problems

[Wynd]

This is my code:

<?
if (!isset($file))
{
    $contents = "You did not specify a file";
}
else
{
    $pFile = fopen($file, "r");
    $contents = fread($pFile, filesize($file));
    fclose($pFile);
}
echo $contents;
?>

The problem is, no matter what I put in, it always prints the error message. What am I doing wrong?