php xml attribute value replace

Say i have an xml file of this nature some data

I wan to replace attributes of each later using one function in php开发者_StackOverflow中文版: example say: replaceAttribute("collections","somecollection,"newcollection");

---

Check this http://www.w3schools.com/DOM/tryit.asp?filename=try_dom_setattribute1 . Hope it helps