Trying to make site map

I am trying to create a ui for a page management script. During this  
step the user chooses which existing page the new page will link  
under. Each record has a field called Page_Above, which references the  
primary key number (id) of the page above it. Currently I have 4  
records in the database:
(id, name, Page_Above)
1, Page1, 0
2, Page2, 1
3, Page3, 2
4, Page4, 1

Here is the pertinent snippet:

		
				include "config.php";
				$conn = mysql_connect($server, $DBusername, $DBpassword);
				mysql_select_db($database,$conn);
				$sql = "SELECT * FROM $Gen WHERE Category = '$Cat' AND Page_Above  
= 0";
				$result = mysql_query($sql, $conn) or die(mysql_error());
				//go through each row in the result set and display data
				while ($pageArray = mysql_fetch_array($result)) {
					
					$prime_id  = $pageArray['id'];
					$Name = $pageArray['Name'];
					print ("<tr><td bgcolor=#ffffff>$Name</td><td bgcolor=#ffffff  
align=left valign=top>");
					
				
							$sql = "SELECT * FROM $Gen WHERE Page_Above = $prime_id";
							$result = mysql_query($sql, $conn) or die(mysql_error());
							//go through each row in the result set and display data
							while ($secpageArray = mysql_fetch_array($result)) {
								// give a name to the fields
								$second_id  = $secpageArray['id'];
								$Name = $secpageArray['Name'];
								print ("$Name<br>");
								
								
							$sql = "SELECT * FROM $Gen WHERE Page_Above = $second_id";
							$result = mysql_query($sql, $conn) or die(mysql_error());
							//go through each row in the result set and display data
							while ($thpageArray = mysql_fetch_array($result)) {
								// give a name to the fields
								$third_id  = $thpageArray['id'];
								$Name = $thpageArray['Name'];
								print ("</td><td>");
								print ("$Name<br>");
								
								
							}
						
						}
					
					}

The results I am getting are incomplete, it only pulls one page per  
level instead of all the pages per level, Like this:
"Page1, Page 2, Page3"
it skips Page4.

When I remove the request for the third level, then I get:
"Page1,Page2,Page4"  Which is correct up to that point. It breaks  
apart when I try to go on the third level.

Any ideas how I can get this to work? In the end there will be 5 levels.
Thanks