<?php
// getCityState.php 
//  Gets the form value from the "zip" widget, looks up the 
//  city and state for that zip code, and prints it for the
//  form
      
	//array that holds some city and state values  
	$cityState = array(
		"21401"=> "Annapolis, MD",
		"21402" => "Annapolis, MD",
		"21044" => "Columbia, MD",
		"21045" => "Columbia, MD",
		"21221" => "Baltimore, MD",
		"21222" => "Baltimore, MD"
	);
	
  //retrieve value of get parameter
  $zip = $_GET["zip"];
  
  //check if zip value exists in array above, and retrieve the city, state values corresponding to the matching zip value
  if (array_key_exists($zip, $cityState))
    echo $cityState[$zip];
  else
	//if doesn't exist, just give an error message
    echo "no matching entry, no matching entry";
?>