func.php
codice:
<?php
//*******Page load dropdown results
function getTierOne()
{
    $result = mysql_query("SELECT DISTINCT tier_one FROM three_drops") 
    ordie(mysql_error());

      while($tier = mysql_fetch_array( $result ))   
        {
           echo '<option value="'.$tier['tier_one'].'">'.$tier['tier_one'].'</option>';
        }
}

//******First selection results
if($_GET['func']=="drop_1"&& isset($_GET['func'])){ 
   drop_1($_GET['drop_var']); 
}

function drop_1($drop_var)
{  
    include_once('db.php');
    $result = mysql_query("SELECT DISTINCT tier_two FROM three_drops WHERE tier_one='$drop_var'") 
    ordie(mysql_error());
    
    echo '<select name="drop_2" id="drop_2">
          <option value=" " disabled="disabled" selected="selected">Choose one</option>';
           while($drop_2 = mysql_fetch_array( $result )) 
            {
              echo '<option value="'.$drop_2['tier_two'].'">'.$drop_2['tier_two'].'</option>';
            }    
    echo '</select>';
    echo "<script type=\"text/javascript\">
$('#wait_2').hide();
    $('#drop_2').change(function(){
      $('#wait_2').show();
      $('#result_2').hide();
      $.get(\"func.php\", {
        func: \"drop_2\",
        drop_var: $('#drop_2').val()
      }, function(response){
        $('#result_2').fadeOut();
        setTimeout(\"finishAjax_tier_three('result_2', '\"+escape(response)+\"')\", 400);
      });
        return false;
    });
</script>";
}

//******Second selection results
if($_GET['func']=="drop_2"&& isset($_GET['func'])){ 
   drop_2($_GET['drop_var']); 
}

function drop_2($drop_var)
{  
    include_once('db.php');
    $result = mysql_query("SELECT * FROM three_drops WHERE tier_two='$drop_var'") 
    ordie(mysql_error());    
    echo '<select name="drop_3" id="drop_3">
          <option value=" " disabled="disabled" selected="selected">Choose one</option>';
           while($drop_3 = mysql_fetch_array( $result )) 
            {
              echo '<option value="'.$drop_3['tier_three'].'">'.$drop_3['tier_three'].'</option>';
            }   
    echo '</select><br>';
    echo '<input type="submit" name="submit" value="Submit" />';
}
?>