http://sqa.fyicenter.com/Online_Test_Tools/Test_urldecode_PHP_Function.php
Testing urldecode() PHP Function
When user data received by a Web server, it is presented in URL
encoding format. If you retrieve this data from
$_SERVER['QUERY_STRING'], you need to decode the data using the
urldecode() function. If This page allows you to learn and test the
urldecode() function to perform URL decoding.