home.php:

<p><a href="city.php?city=New_York_City">New York</a></p>

<p><a href="city.php?city=Boston">Boston</a></p>

city.php:

<p>Welcome to <?php echo $_GET['city'] ?> !</p>

OR -

home.php:

<p><a href="city.php?city=<?php echo urlencode("New York City"); ?>">New York</a></p>

<p><a href="city.php?city=Boston">Boston</a></p>

<p><a href="city.php?city=Rockville">Rockville</a></p>

city.php:

<p>Welcome to <?php echo urldecode($_GET['city']); ?> !</p>

Simple PHP $_GET  variable

php

PHP