need some help (executing a python script with variable from php)

[haxorflex]

I have a little problem with the following,

i made the following script php script to execute a python file on my server and parse a variable to it.. but somehow the var never ends up to python

<?php
if ($_POST) {

import_request_variables('p', 'p_');
$net = $_POST['net'];

$result = exec("/usr/bin/python st/st.py $net &> st/pylog.txt");
echo $result;

$myFile = "st/pylog.txt";
$fh = fopen($myFile, 'r');
$theData = fread($fh, filesize($myFile));
fclose($fh);
echo $theData;

}

?>

<form action="" method="post">
    NET:  <input type="text" name="net" />
    <input type="submit" value="submit!" />
</form> 

Can someone tell me what i'm doing wrong?

Thanks in advance