you'll probably want to parse the XML file in PHP, then find your node using XPATH.

There are plenty of tutorials on each, if you hit the search engines for "PHP XPATH".

And I do recommend the SimpleXML [ca3.php.net] class, which has an XPATH [ca3.php.net] method.

Thanks httpwebwitch.
I have this .js file that I think will pretty much do for what I need. As it stands, if I type a name <title> into my form, the .js file looks through my XML file for a matching name & returns that name to my page (which isn't achieving much really!)
How can I adapt the code so that it returns the rest of the child elements along with it ie. <author> <book_title>
Thank you to any kind expert who can help me out!

window.onload = loadIndex;
function loadIndex() { // load indexfile
if (document.implementation && document.implementation.createDocument) {
xmlDoc = document.implementation.createDocument("", "", null);
xmlDoc.load("index.xml");
}
else if (window.ActiveXObject) {
xmlDoc = new ActiveXObject("Microsoft.XMLDOM");
xmlDoc.async = "false";
xmlDoc.load("index.xml");
}
}
function searchIndex() { 
if (!xmlDoc) {
loadIndex();
}
var searchterm = document.getElementById("searchme").value;
var allitems = xmlDoc.getElementsByTagName("title");
 results = new Array;
if (searchterm.length < 2) {
alert("Enter at least two characters");
} else {
for (var i=0;i<allitems.length;i++) {
var name = allitems[i].lastChild.nodeValue;
var exp = new RegExp(searchterm,"i");
if ( name.match(exp) != null) {
results.push(allitems[i]);
}
}
showResults(results, searchterm);
}
}
function showResults(results, searchterm) {
if (results.length > 0) {
var resultshere = document.getElementById("resultshere");
var header = document.createElement("h5");
var list = document.createElement("ul");
var searchedfor = document.createTextNode("You've searched for "+searchterm);
resultshere.appendChild(header);
header.appendChild(searchedfor);
resultshere.appendChild(list);
for (var i=0;i<results.length;i++) {
var listitem = document.createElement("li");
var item = document.createTextNode(results[i].lastChild.nodeValue);
list.appendChild(listitem);
listitem.appendChild(item);
}
} else {
var resultshere = document.getElementById("resultshere");
var para = document.createElement("p");
var notfound = document.createTextNode("Sorry, I couldn't find anything like "+searchterm +"!");
resultshere.appendChild(para);
para.appendChild(notfound);
}
}

[edited by: httpwebwitch at 3:06 am (utc) on Jan. 26, 2009]
[edit reason] normalized font size [/edit]

var item = document.createTextNode(results[i].lastChild.nodeValue);

That still points you to the 'title' element which you matched; to find others jump to the parent then find the child:

var itemobject = results[i].parentNode; 
var item_title = itemobject.getElementsByTagName('title')[0];
var item_summary = itemobject.getElementsByTagName('summary')[0];
etc.