PHP gallery paging

<?php

	// OPEN THE CONNECTION
	//
		include ("../var/db_connect.php");

	// CREATE AN ARRAY WITH ALL THE IMAGE ID'S IN THE GALLERY
	//
		$query = ("SELECT id FROM images WHERE gallery_id=(SELECT gallery_id FROM images WHERE id='".$_REQUEST['id']."') ORDER BY id DESC");
		$result = mysql_query($query);
		$images_in_gallery = array();

		while ($row = mysql_fetch_array($result))
		{
			array_push($images_in_gallery, $row['id']);
		}

	// ASSIGN TEXT FOR THE LINKS, THIS CAN BE CHANGED TO IMAGES
	//
		$next_text = 'Older';
		$prev_text = 'Newer';

	// CREATE THE LINK
	//
		$next_link = "<a href=\"?id=".$images_in_gallery[array_search($_REQUEST['id'], $images_in_gallery)+1]."\">$next_text</a>";
		$prev_link = "<a href=\"?id=".$images_in_gallery[array_search($_REQUEST['id'], $images_in_gallery)-1]."\">$prev_text</a>";

	// DISABLE HYPERLINKING ON FIRST AND LAST IMAGES IN THE GALLERY FOR APPROPRIATE LINKS
	//
		if ($next_link == "<a href=\"?id=\">$next_text</a>")
		$next_link = "$next_text";
		if ($prev_link == "<a href=\"?id=\">$prev_text</a>")
		$prev_link = "$prev_text";

	// GET THE IMAGE CAPTION AND ALT TAG
	//
		$query = ("SELECT caption FROM images WHERE id='".$_REQUEST['id']."'");
		$result = mysql_query($query);
		$row = mysql_fetch_array($result);

	// CLOSE THE CONNECTION
	//
		mysql_close($con);
?>

	<!-- Show some ouput for testing -->

	<br />	<br />

	<?php echo $prev_link; ?>

	<?php echo $next_link; ?>

	<br />	<br />

	<img src="image.php?id=<?php echo $_REQUEST['id']; ?>" alt="<?php echo $row['caption']; ?>" />

	<p><?php echo $row['caption']; ?></p>

	<!-- --------------------------- -->