//the checkbox
<input name="checkGroup[]" type="checkbox" id="chks1" value="1" />
<input name="checkGroup[]" type="checkbox" id="chksl" value="2" />
<input name="checkGroup[]" type="checkbox" id="chksl" value="3"/>

//this is the array
<? 
while(list ($key,$val) = @each ($_REQUEST['checkGroup'])) {
 global $database;
          $q ="DELETE FROM cos_sys_main_reminder WHERE reminder_id='$val'";
          $result = $database->query($q);
}
?>