//栏目Ajax做加载
public function ajaxlist(){
 //echo "http://www.域名.com/index.php?a=Indexc=Indexm=ajaxlist";
 //echo "hr>";
 $data = Q('sum');
 $where = array();
 $where['cid'] = 33;
 $rongyuList = M('content')->limit($data,2)->where($where)->select();
 $data['stat'] = 1;
 $data = $rongyuList;
 $this->ajax($data);
 //也可以手动把想要的字段拼接成字符串 
 /*echo "[";
 foreach($rongyuList as $k){
  echo "{"."\""."title"."\"".":"."\"".$k['title']."\"".","."\""."description"."\"".":"."\"".$k['description']."\"".","."\""."cid"."\"".":"."\"".$k['cid']."\""."}".",";  
 }
 echo "]";*/
 }

script type='text/javascript'>
/*ajax*/
(function(){
//发送数据 
var url = "__WEB__"+"?a=Indexc=Indexm=ajaxlist";
var oSum = ''; 
$('a.ajaxBut').click(function(){
 oSum = $('div.zizhiListContBox>a').size();
 $.post(url,{sum:oSum},function(result){
 console.log(result);
 eval("var info="+result);
 for(var key in info){
   oStr = "a href='"+"__WEB__"+"?a=Indexc=Indexm=contentmid=1cid=33aid="+info[key]['aid']+""+"'>h3 class='f100 f16 ts500'>"+info[key]['title']+"/h3>p>"+info[key]['description']+"/p>span class='b parb'>/span>/a>";
   $('div.zizhiListContBox').append(oStr);
 };
 });
});
})();
/script>

!-- 示例：HTML -->
dl class="pr keshi" >
 dt class="pa">科室：/dt>
 dd class="pa">
  select name='keshi' class='m_keshi'>
   option value='0'>--请选择科室--/option>
  /select>
  select name='zhuanjia' class='m_zhuanjia'>
   option>--请选择专家--/option>
  /select>
 /dd>
/dl>

//示例控制器
/* Ajax请求栏目列表 */
public function ajaxlanmu(){
 $lanmuList = M('category')->where('pid=142')->select();
 $this->ajax($lanmuList);
}
public function ajaxzhuanjia(){
 $where = array();
 $data = Q('sum');
 $data = $data ? $data : 143;
 $where['cid'] = $data;
 $zhuanjiaList = M('guahao')->where($where)->select();
 $this->ajax($zhuanjiaList);
}

script>
(function(){
var lanmuUrl = "__WEB__"+"?a=Indexc=Indexm=ajaxlanmu";
var zhuanjiaUrl = "__WEB__"+"?a=Indexc=Indexm=ajaxzhuanjia";
var oSum = oStr = oStr2 = oVal = oKong = info2 = oCid = '';
/* lanmu */
$.post(lanmuUrl,function(result){
 eval("var info="+result);
 for(var key in info){oStr += "option value='"+info[key]['catname']+"' cid='"+info[key]['cid']+"'>"+info[key]['catname']+"/option>";};
 $('dl.keshi').find('select.m_keshi').append(oStr);
});
/* zhuanjia */
$('dl.keshi').find('select.m_keshi').change(function(){
 oVal = $(this).find('option:selected').val();
 if(oVal == 0){
  $('dl.zhuanjia').find('select.m_zhuanjia').html("option>--请选择专家--/option>");
 }else{
  oCid = $(this).find('option:selected').attr('cid');
  $.post(zhuanjiaUrl,{sum:oCid},function(result){
   eval("info2="+result);
   oStr2 = '';//注意这里要清空第一次请求的数据
   for(var key2 in info2){
    oStr2 += "option value='"+info2[key2]['title']+"'>"+info2[key2]['title']+"/option>";    
   };
   $('dl.zhuanjia').find('select.m_zhuanjia').html(oStr2);
  });
 };
});
})();
/script>