Creating a link to Full Size Image

I'm displaying images from my db on the show.php page. I'd like to have that image linked to the full size image. Could you tell me the php call to do that? Here's the image call on the show.php page:

<?php
if(item_fullsize()) {
    echo item_fullsize();
}
?>

Hi,

The follow should do what you want. I have tested this in 1.3.1

<ul>
	<?php
		$item = get_current_item();
		$files = $item->Files;

		foreach ($files as $file)
		{
			if ($file["has_derivative_image"] = 1)
			{
				echo '<li>';
				echo '<a href="/archive/files/' . $file["archive_filename"] . '">' . $file["original_filename"] . '</a>';
				echo '</li>';
			}
		}
	?>
</ul>

Umm, that isn't what I was expecting. What that gave me was a bulleted list of links of all the images associated with each record.

Let me see if I can be clearer. I am displaying the main image on the show.php page. I am displaying it at a smaller size than the full size image using the max-width and max-height attributes in the css. However, I'd like a person to be able to click on that displayed image and get the full size image in a new browser window. So, essentially what I want is this:

<a href="full_size.jpg"><?php
if(item_fullsize()) {
    echo item_fullsize();
}
?></a>

But I don't know how to do that in php using Omeka's nomenclature.

I think this should work:
<?php echo display_files_for_item(array('imageSize'=>'fullsize')); ?>

Andy, that does it but it also displays ALL the images in that record. I just want to display the first one, which is the artwork (the others are related images shown elsewhere).

<?php

$files = $item->Files;
$firstFile = $files[0];

echo display_file($firstFile,array('imageSize'=>'fullsize'));
?>

Andy, that worked! Thanks very much. I added an if statement just in case there was no image.