PHP: Wordpress nextgen gallery template file flexslider with carousel thumbnails

gistfile1

<?php 
/**
Template Page for the gallery overview

Follow variables are useable :

	$gallery     : Contain all about the gallery
	$images      : Contain all images, path, title
	$pagination  : Contain the pagination content

 You can check the content when you insert the tag <?php var_dump($variable) ?>
 If you would like to show the timestamp of the image ,you can use <?php echo $exif['created_timestamp'] ?>
**/
?>
<?php if (!defined ('ABSPATH')) die ('No direct access allowed'); ?><?php if (!empty ($gallery)) : ?>
	
				<div class="slider">
				    
				    <div id="slider" class="flexslider">
					    <ul class="slides">    
					    
					<?php foreach ( $images as $image ) : ?>
					<?php if ( !$image->hidden ) { ?><li>
										<img title="<?php echo $image->alttext ?>" alt="<?php echo $image->alttext ?>" src="<?php echo $image->imageURL ?>"  />
										<span class="caption"><?php echo $image->alttext ?></span>
										<span class="credit"><?php echo $image->description ?></span>
									</li>
					<?php } ?>
					<?php if ( $image->hidden ) continue; ?>
					<?php if ( $gallery->columns > 0 && ++$i % $gallery->columns == 0 ) { ?>
					<?php } ?><?php endforeach; ?>
					
						</ul>
					</div>
					
					<!-- Thumbnails -->
					
					<div id="carousel" class="flexslider">
						<ul class="slides"><?php foreach ( $images as $image ) : ?><?php if ( !$image->hidden ) { ?>
							
							<li><img title="<?php echo $image->alttext ?>" alt="<?php echo $image->alttext ?>" src="<?php echo $image->thumbnailURL ?>" <?php echo $image->size ?> /></li>
					
					<?php } ?>
					<?php if ( $image->hidden ) continue; ?>
					<?php if ( $gallery->columns > 0 && ++$i % $gallery->columns == 0 ) { ?>
					<?php } ?>
					<?php endforeach; ?></ul>
					</div>
					
				<?php endif; ?>
				
				</div>

Thanks for such great help, but wanted to know about below variables.

$gallery     : Contain all about the gallery
$images      : Contain all images, path, title
$pagination  : Contain the pagination content

So $gallery is my gallery id, what we have to store in $images & $pagination ?