ActionScript 2.0 :: LoadVars - Getting Variable From PHP?

I try to get a variable from php : I have a button with :
on (release) {
$myLoadVars = new LoadVars();
$myLoadVars_received = new LoadVars();
$myLoadVars.var_to_php = myComboBox.getSelectedItem().label;
$myLoadVars.sendAndLoad ( "script.php",$myLoadVars_received);
$affich_var = $envelope_received.var_from_php; }

PHP //
script.php :
<? $result = mysql_query( "select counter from data_base where data1='".$_POST['var_to_php']."'");
$counter = mysql_fetch_row($result);
echo ("&var_from_php=$counter[0]");
?>

My result of all this : nothing happens. no variable is received from php. (The is no request ( from the firewall ) from flash to access the internet). So I think the error is around the sendandload. By the way, the php script works perfectly with loadVariablesNum.