How do i search within a xml file?

[admin]

hi,i'm new to XML. I have this problem regarding searching within a XML file.theidea is that my search will be based on the keyword enteredinby the user from a HTML form. the keyword is then used to search allthequestion nodes and the choice nodes within a XML file. once the matchisfound, i will have to display the results.But i don't know how to do so - especially the part of searching xml file.Cananyone help me in this? Attached is the xml file. Your help is much appreciated.---------------------------<?xml version="1.0"?><!--<?xml:stylesheet href=http://forums.devx.com/archive/index.php/"QuizXsl.xsl" type="text/xsl"?>--><Quiz><QuestionNo ID="1"><Question>What does multimedia means?</Question><Choice ID="A">multiple media on the web.</Choice><Choice ID="B">an application that contains media such as audio, video,graphics, text.</Choice><Choice ID="C">media that is completely animated.</Choice><Choice ID="D">media with rich text format (*.rtf)</Choice><Answer>B</Answer></QuestionNo><QuestionNo ID="2"><Question>What elements can't be inserted into a html page?</Question><Choice ID="A">text</Choice><Choice ID="B">picture</Choice><Choice ID="C">sound</Choice><Choice ID="D">paper</Choice><Answer>D</Answer></QuestionNo></Quiz>