<?php
$aPostCode=array();
$aTownName=array();
$aPostCode[1]=2000;	$aTownName[1]="Szentendre";
$aPostCode[2]=2009;	$aTownName[2]="Pilisszentlászló";
$aPostCode[3]=2011;	$aTownName[3]="Budakalász";
$aPostCode[4]=2013;	$aTownName[4]="Pomáz";
$aPostCode[5]=2014;	$aTownName[5]="Csobánka";
...
$aPostCode[3362]=9982;	$aTownName[3362]="Kétvölgy";
$aPostCode[3363]=9982;	$aTownName[3363]="Orfalu";
$aPostCode[3364]=9983;	$aTownName[3364]="Alsószölnök";
$aPostCode[3365]=9983;	$aTownName[3365]="Szakonyfalu";
$aPostCode[3366]=9985;	$aTownName[3366]="Felsőszölnök";

header("Content-type:text/xml");
echo "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>";
echo "<!DOCTYPE towns [<!ELEMENT towns (town+)><!ELEMENT town (postcode,name)><!ELEMENT postcode (#PCDATA)><!ELEMENT name (#PCDATA)>]>";
echo "<towns>";
if(isset($_GET["postcode"])){
   $i=floor($_GET["postcode"]);
   foreach($aPostCode as $idx=>$data)
      if($data==$i){
         echo "<town>";
         echo "<postcode>".$aPostCode[$idx]."</postcode>";
         echo "<name>".$aTownName[$idx]."</name>";
         echo "</town>";
         }
   }
elseif(isset($_GET["town"])){
    $sz=mb_strtolower(trim($_GET["town"]),"UTF-8");
    if($sz!="")
    foreach($aTownName as $idx=>$data)
      if(substr(mb_strtolower($data,"UTF-8"),0,strlen($sz))==$sz){
         echo "<town>";
         echo "<postcode>".$aPostCode[$idx]."</postcode>";
         echo "<name>".$aTownName[$idx]."</name>";
         echo "</town>";
         }
   }
echo "</towns>";
?>