onSelect: Aufruf neuer Seite mit Variablen

[XaraX]

if((isset($_POST[x])||isset($_GET[x]))&&(isset($_POST[y])||isset($_GET[y]))&&(isset($_POST[z])||isset($_GET[z])))
   header("Location: http://www.wünsch.dir.was.de");
else
   {
   echo "<form action="reference.php?x=$x&y=$y&z=$z" method="post" target="">";
   echo "<select name="x" style="WIDTH: 150px" onChange="submit()"><option value="empty">Select...</option><option value="all">All Applications</option></select>";
   echo "<select name="y" style="WIDTH: 150px" onChange="submit()"><option value="empty">Select...</option><option value="all">All Products</option></select>";
   echo "<select name="z" style="WIDTH: 150px" onChange="submit()"><option value="empty">Select...</option><option value="all">All Countries</option></select>";
   echo "</form>";
   }

Gruß aus Berlin!
eddi