Highest count

[batman]

Hello,

What I am wanting to do is get a query from the database then do a count on a particular field on all rows. It is for a "Hot Seller" type thing. What I have is when someone orders a particular product it will add popularity to that item. What I then want to do is, for the hot seller, do a query of all products then pick out the one that has the highest popularity. 

Here is my code that does the query.

// start border
sb("100%","Hot Seller",$colour_1,$colour_2);

				// list 1 random product
                                                                  If (!empty($cat_id))
                                                        {
				$query5 = "select * from ".$prefix."store_inventory order by rand() desc LIMIT 1"; 
				}
                                                                  If (empty($cat_id))
                                                        {
				$query5 = "select * from ".$prefix."store_inventory order by rand() desc LIMIT 1"; 
				}

                                                                  $result5 = mysql_query($query5);


				// start table for neat display
				echo"<table align=\"left\" width=\"100%\" border=\"0\" cellspacing=\"0\" cellpadding=\"5\">";
				while($row5 = mysql_fetch_array($result5)){ 

					$title=$row5["title"];
					$product=$row5["product"]; 
					$title=stripslashes($title);
					$image = $row5["image"];
                                                                                $description = $row5["description"];
                                                                                $description=stripslashes($description);
		                                          $description=substr($description,0,50);
                                                                                 if (!file_exists("$site_dir/images/" . "thumb_$image")){
			                             $thumb=new thumbnail("$site_dir/images/$image");
			                             $thumb->size_auto(75);	
			                             $thumb->jpeg_quality(75);
			                             $thumb->save("$site_dir/images/thumb_$image");}



				// display info
				echo"<tr><td width=\"90\" align=\"left\"><a href=\"view_product.php?product=$product\" target=\"_self\"><img src=\"images/thumb_$image\" border=\"0\"></a></td>";
				echo"<td align=\"left\" valign=\"top\"><a href=\"view_product.php?product=$product\" target=\"_self\"><b>$title</b></a><br><br><b>Description:</b><br>$description";
                                                                           if(strlen($description)>=50)
					{echo"..";}
		                                           if(empty($description))
					  {echo"n/a";}
                                                                  echo"</td>";
                                                                  echo"<td width=\"90\" align=\"left\"><a href=\"view_product.php?product=$product\"><img src=\"images/more_info.gif\" border=\"0\"></a></td>";
                                                                  echo"</tr>";
				}// end while
				echo"</table>";
// end border
eb();
echo"<br>";

Now where I'm stumped is where and how to add the highest count thing.

Thanks for all replies.
-Blake