function sxml2arr($xml)
	{
		$arr = (array)$xml;
		foreach ($arr as $key => $value) {
			if($value instanceof simplexmlElement || is_array($value))
			{
				$arr[$key] = sxml2arr($value);
			}
		}
		return $arr;
	}

	function arr2xml($arr,$node=NULL)
	{
		if($node === NULL)
		{
			$xml = new simplexmlElement("<?xml version='1.0' encoding='utf-8'?><geng></geng>");			
		}
		else
		{
			$xml = $node;
		}
		foreach ($arr as $key => $value) 
		{
			if(is_array($value))
			{
				if(is_numeric($key))
				{
					arr2xml($value,$xml->addChild('item'.$key));
				}
				else
				{
					arr2xml($value,$xml->addChild($key));
				}
			}
			else if(is_numeric($key))
			{
				$xml->addChild('item'.$key,$value);
			}else
			{
				$xml->addChild($key,$value);
			}
		}		
		return $xml;
	}