<?php
$id1=$_GET['id1'];
$id2=$_GET['id2'];
$level=$_GET['l'];

if($level==1) //Get level 1 data
    $sql="select distinct id1 as id from cascading order by id1";
else if($level==2) //Get level 2 data
    $sql="select distinct id2 as id from cascading where id1=$id1 order by id2";
else //Get level 3 data
    $sql="select distinct id3 as id from cascading where id1=$id1 and id2=$id2 order by id3";
  
$cn=mysql_connect('localhost', 'root', '123456');

mysql_selectdb('rsywx');
$res=mysql_query($sql);
$arr=array();
while($row=mysql_fetch_object($res))
{
    $key="Option ".$row->id;
    $value=$row->id;
    $arr[$key]=$value;
}

$j_ret=json_encode($arr);

echo $j_ret;
?>