parse url param key value

function convertUrlQuery($query)
	{
		$queryParts = explode('&', $query);
	
		$params = array();
		foreach ($queryParts as $param)
		{
			$item = explode('=', $param);
			$params[$item[0]] = $item[1];
		}
	
		return $params;
	}
function use($key)
      {
                 $url = $url['url'];
		 $arr = parse_url($url);
		 $arr_query = $this->convertUrlQuery($arr['query']);
		 return $arr_query[$key];            
      }