Process multiple forms

Question

Hi i'm using an jscript autosave script for my Form and I'm working on the backend submission part. Although its only 8 separate entries to be autosave, how can I $_POST with just one query... example user fills in there FirstName in script autosaves now the i'd like the backend script to do something like (see below). Is there a way to $_POST fieldname automatically without filling it in?

if ($_POST['INSERT FIELD NAME'] != '') {
$_POST['INSERT FIELD NAME'] as $key => $value
mysql_query("UPDATE table SET $key '='".mysql_real_escape_string(stripslashes($value))."' WHERE id=$id");
}