parsing XML in PHP4

Hi,

I am trying to parse an XML document using PHP and I am in need of some advice.
I found some blogs, descirptions on this matter, but would appreciate some more help on it.
I set up the request sending with curl and the want to parse the respond XML using PHP. I am using the php xml parser, but need some help to set it up.

$this->m_xmlParser = xml_parser_create();
xml_parser_set_option($this->m_xmlParser, XML_OPTION_TARGET_ENCODING, 'UTF-8');
xml_parser_set_option($this->m_xmlParser,XML_OPTION_SKIP_WHITE, 1);

Next, what I know, couple of functions must be defined to handle the start, end Elements and the data itself. I only found tutorials where you expecting to know the tagnames, but that is meaningless, as I need to parse the respond without any knowledge on its structure and building up its XML hierarchy with tagnames, attributes and such.
I need to write these handling functions, so when it actually finds ie: a starting element firing a general callback function which build up the XML tree/structure, the same with end elements, attributes and such.
Can someone help me with some information how to do this, please?
Any description, info, light on this matter will be appreciated
Thanks
ben