passing data in a form

Can someone explain this to me. In newbie terms please - so that I understand it rather than just paste it in. Thanks This is my code: <snip> $sql ="SELECT DISTINCT zone FROM targetlist where valid_user = '$valid_user' "; $result = @mysql_query($sql) or die(mysql_error()); $num = @mysql_num_rows($result); while ($row =mysql_fetch_array($result)){ $zone = $row['zone']; $display_block .="<input type='checkbox' name=\"zone_selected\" value=\"$zone\">$zone<br>"; } <end snip> This displays the zones that I have available as checkboxes in my form. If I select one checkbox all works as expected using : $zone_selected = $_POST[zone_selected]; However, if I select 2 or more checkboxes, I only get the results of the last option selected. How can I add a "while there is data in $zone_selected repeat them on the page...." sort of thing. Many thanks fr any help Jim