fopen at w2k3 server

[kwh]

i have trouble using fopen on win2k3. i assigned all necessary priv. to the corresponding files, but php keeps saying that it failed to open stream, because permission is denied. here is the url: http://www2.mupad.de/minishop/GetOrderInfo.php
i can't figure out what else to do, since i did all the priviledges stuff. is there maybe a special way to allow file ops on w2k3?
here is the content of the script:

$tid = "c:\htdocs\minishop\$tcphTransactionID";

if (file_exists ($tid)) {

$TX = fopen ($tid, "r");
if ($TX) {
$TXdaten = fread ($TX,filesize ($tid));
print ($TXdaten);
fclose($TX);
}

readfile ($tid);

}

else {
print "Transaktionsdatei $tid nicht vorhanden";
die;
}

?>

cu kai

[hessian]

What is the value of $tcphTransactionID?

From the error on your page, it looks like you are trying to open a directory and that $tcphTransactionID is empty.

Maybe you are running your variables together?
is the Var just $tcph?

If that is true you should be doing it like this:
$tid = "c:\htdocs\minishop\".$tcph."TransactionID";