Build URL query params as http_build_query build a query url the difference is that this function is array recursive and compatible with PHP4

url_build_query.php

<?php
/**
 * Build URL query params
 * as http_build_query build a query url the difference is 
 * that this function is array recursive and compatible with PHP4
 *
 * @author Marco Cesarato <cesarato.developer@gmail.com>
 * @param $query
 * @param string $parent
 * @return string
 *
 * @example
 * $p = array('abbreviations' => array('google' => 'ggle', 'facebook' => array('abb_key' => 'fbook', 'fcbk')), 'key' => 'value');
 * echo url_build_query($p);
 */
function url_build_query($query, $parent = null){
	$query_array = array();
	foreach($query as $key => $value){
		$_key = empty($parent) ?  urlencode($key) : $parent . '[' . urlencode($key) . ']';
		if(is_array($value)) {
			$query_array[] = url_build_query($value, $_key);
		} else {
			$query_array[] = $_key . '=' . urlencode($value);
		}
	}
	return implode('&', $query_array);
}