If you are using flash MX 2004 / Flash 8 and probably using XML in your project, please do try this website
I must thank the people who have made the source code as open source. And the best part is you have 2 flavours to choose, AS1 and AS2 implementation of XPath as downloads.
If you are lost or worried about the syntax/regular expression I suggest these sites, They are really good with sounding examples.
- Site – http://www.zvon.org/xxl/XPathTutorial/Output/examples.html
- Site – http://www.w3schools.com/xpath/default.asp
BTW, the implementation doesn't stop with Flash, you can also use with your dynamic html pages too..