PHP / XML parsing

[pinkspider]

Hi- I have a question regarding XML parsing with PHP. I'm doing a music_review.php which is going to parse music reviews, which are stored via PHP. I've already got the parser, but I don't know how to make it look only at a specific review.

<?php

$xml_name = $get
   // HOW TO GET THIS TO PICK THE RIGHT XML FILE? XML NAME STORED IN $GET
$xml_file = "review.xml";

$xml_headline_key = "*REVIEW*CONTENT*HEADLINE";
$xml_review_key = "*REVIEW*CONTENT*REVIEW";
$xml_tracklist_key = "*REVIEW*CONTENT*TRACKLIST";

$story_array = array();

$counter = 0;
class xml_story{
    var $headline, $description, $tracklist;
}

function startTag($parser, $data){
    global $current_tag;
    $current_tag .= "*$data";
}

function endTag($parser, $data){
    global $current_tag;
    $tag_key = strrpos($current_tag, '*');
    $current_tag = substr($current_tag, 0, $tag_key);
}

function contents($parser, $data){
    global $current_tag, $xml_headline_key, $xml_description_key, $xml_tracklsit_key, $counter, $story_array;
    switch($current_tag){
        case $xml_headline_key:
            $story_array[$counter] = new xml_story();
            $story_array[$counter]->headline = $data;
            break;
        case $xml_review_key:
            $story_array[$counter]->review = $data;
            $counter++;
            break;
        case $xml_tracklist_key:
            $story_array[$counter]->tracklist = $data;
            $counter++;
            break;
    }
}

$xml_parser = xml_parser_create();

xml_set_element_handler($xml_parser, "startTag", "endTag");

xml_set_character_data_handler($xml_parser, "contents");

$fp = fopen($xml_file, "r") or die("Could not open file");

$data = fread($fp, filesize($xml_file)) or die("Could not read file");

if(!(xml_parse($xml_parser, $data, feof($fp)))){
    die("Error on line " . xml_get_current_line_number($xml_parser));
}

xml_parser_free($xml_parser);

fclose($fp);

?> 

And then later on in the page, buried in the layout of HTML, which I'll omit...

<div id="content"><p><?php
for($x=0;$x<count($story_array);$x++){
    echo "\t<p>" . $story_array[$x]->headline . "</p>\n";
    echo "\t\t\n";
    echo "\t<p>" . $story_array[$x]->description . "</p>\n";
}
?> 

This would work great, except I only want to take out ONE entry at a time. How to do this? Anybody? Please help!