Create the show all link to pass a QS Parameter:
<a href="results.php?showall=1">Show All</a>
Then change the following line:
$WADAProducts = mysql_query($query_limit_WADAProducts, $localhost) or die(mysql_error());
to:
if(isset($_GET['showall']) && $_GET['showall']== 1) {
$WADAProducts = mysql_query($query_WADAProducts, $localhost) or die(mysql_error());
} else {
$WADAProducts = mysql_query($query_limit_WADAProducts, $localhost) or die(mysql_error());
}