JSONPの定義と基本的な使い方 | Codetter（こーどったー）

callback(
	{"category":[
			{"catid": "001","catname": "test1"},
			{"catid": "002","catname": "test2"},
			{"catid": "003","catname": "test3"},
			{"catid": "004","catname": "test4"},
			{"catid": "005","catname": "test5"}
		]
	},
	{"category_origin": [
			{"catid": "001","catname": "test1"},
			{"catid": "002","catname": "test2"},
			{"catid": "003","catname": "test3"},
			{"catid": "004","catname": "test4"},
			{"catid": "005","catname": "test5"}
		]
	}

);


	$(function(){
		$.getJSON('http://hogehoge.com/sample.json?callback=?')
	});
	
	var callback = function(data){
		var obj;
		$(data.category).each(function(key,value){
			var val = this.catid;
			var text = this.catname;
			obj += '<option val="' + val + '">' + text + '</option>';
		});
	$('#form_cat').html(obj);
	};