Parsing info from a form

Ok, I understand that if I send a form to a script to get the values, I write something like

$AMT = $_POST[AMT];

but the form has a hundred variables. Is there a way to do it automatically?

like
foreach($key => $value) {
$key = $value;
}

So that later in the script I can manipulate the keys as if I had done $AMT = $_POST[AMT];