ajax傳回下拉菜單預設選中

function get_category(id,next,select_id){

if(id == 0){

var html = "<option value='0'>請選擇商品分類</option>";

$('#'+next).empty().html(html);

return false;

}

$.ajax({

type : "GET",

url : '/index.php?m=Home&c=api&a=get_category&parent_id='+ id,

dataType:'json',

success: function(data) {

            var html = "<option value='0'>請選擇商品分類</option>";

if(data.status == 1){

for (var i=0 ;i<data.result.length;i++){

html+= "<option value='"+data.result[i].id+"'>"+data.result[i].name+"</option>";

}

}

$('#'+next).empty().html(html);

            (select_id > 0) && $('#'+next).val(select_id);//預設選中<+++++++++++++++++++++++

}

});

}