Getting JavaScript elements to work

<?php
/*******************************************************************************
	Filename				: imagefunctions.php

	Called by				: 

	Created					: 30 March 2004 (16:59:40)
	Created by				: Rick Holmes/NinthVector LLC

	QueryString Collection	: 
	Form Collection			: 
	Session Variables		: 
	Database Tables			: 
	Stored Procedures		: 
	Include Files			: 


	Comments				: provides AJAX 'back end' for image gallery for NHpets.com
*******************************************************************************/	

class DirectoryItems {
	public $filearray = array();
	private $directory;
	private $imagetypes = array('jpg', 'jpeg', 'gif', 'png');
	
	function __construct($directory) {
		$this->directory = $directory;
		$this->getDirectoryItems();
	}

	private function getDirectoryItems() {
		if (is_dir($this->directory)) {
			$d = opendir($this->directory) or die("Failed to open $this->directory");
			while (false !== ($f = readdir($d))) {
				if (is_file($this->directory . $f)) {
					$ext = substr($f, strpos($f, ".") + 1);
					if (in_array($ext, $this->imagetypes)) {
						array_push($this->filearray, $f);
					}	
				}
			}
		}
	}

	public function encodeJSON() {
		return json_encode($this->filearray);
	}
}


// get directory name from Ajax request
if (isset($_GET['page'])) {
	
	$page = $_GET['page'];
	$directory = "../photos/$page/";
	
	$files = new DirectoryItems($directory);
	echo $files->encodeJSON();

}

// check directory for image files


// return JSON string of image names


?>

	$directory = "../photos/$page/";

	$directory = "assets/templates/nhpets/photos/$page/";

	$directory = "/home/domain/www/assets/templates/nhpets/photos/$page/";

src="photos/services/DSCN0045.jpg"

src="assets/templates/nhpets/photos/services/DSCN0045.jpg"

// does Ajax call to load proper images into array of preloaded images
		getImages: function() {
			// first get page name from body id
			var page = document.body.id;
			if (page == 'directions') return;
			// php url
			var url = '../ajax/imagefunctions.php?page=' + page;
			
			$.getJSON(url,
				function(data) {
					jQuery.each(data, function(i, val) {
						var id = val.substr(0, val.lastIndexOf('.'));
						path = 'photos/' + page + '/' + val;
						imageArray[i] = $('<img>').attr('src', path).attr('id', id).attr('class', 'galleryphoto');
						});
					$('.galleryphoto').replaceWith(imageArray[0]);
					$('#image_minus').css('display', 'none')
				});			
		},
		
		changeImage: function(direction) {
			var count = imageArray.length;
			if (direction == 'plus') {
				if (imageIndex < count - 1) {
					imageIndex = imageIndex + 1;
					if ($('.galleryphoto')) {
						$('.galleryphoto').replaceWith(imageArray[imageIndex]);
					}
					$('#image_minus').css('display', 'block');
				} else {
					$('#image_plus').css('display', 'none');
				}
			} else if (direction == 'minus') {
				if (imageIndex > 0) {
					imageIndex = imageIndex - 1;
					if ($('.galleryphoto')) {
						$('.galleryphoto').replaceWith(imageArray[imageIndex]);
					}
					$('#image_plus').css('display', 'block')	
				} else {
					$('#image_minus').css('display', 'none')
				}
			}
		}
		
	}
}();

path = 'photos/' + page + '/' + val;