รบกวนสอบถาม วิธี แสดงข้อมูลการจองห้องประชุมเป็น ตาราง ครับ

<?php
					  include("conDB.php");
						$sql1 = mysql_query("SELECT * FROM reservation WHERE room_id = 1 &&   re_date = '$_GET[re_date]' order by re_id asc ");
						$sql2 = mysql_query("SELECT * FROM reservation WHERE room_id = 2 && re_date = '$_GET[re_date]' order by re_id asc ");
						
						
					 for($i=16;$i<=36;$i++){
							echo "<tr>";
								echo "<td>";
									echo floor($i/2).".";
									echo $minute = ($i%2==0) ? "00" : "30";		
								echo "</td>";
					
								while($rs1 = mysql_fetch_array ($sql1)){
								$show1 = $rs1[re_starttime];
								$show2 = $rs1[re_endtime];
								}
								if ($i>=$show1 && $i<=$show2){
								
								echo "<td bgcolor=red>";
								echo "</td>";
								}
							
							else { echo "<td bgcolor=gray>";
								echo "</td>";}
								
								while ($rs2 = mysql_fetch_array ($sql2)){
								
								$show3 = $rs2[re_starttime];
								$show4 = $rs2[re_endtime];}
								if ($i>=$show3 && $i<=$show4){
								
								echo "<td bgcolor=red>";
								echo "</td>";
								}
							
							else { echo "<td bgcolor=gray>";
								echo "</td>";}
							
					echo "</tr>";	}
						
					  ?>