// lifteffect({
// 	"control1": ".lift2", 						  //侧栏电梯的容器
// 	"control2": "#ccc",                           //需要遍历的电梯的父元素
// 	"target": [".dianti1",".dianti2",".dianti3"], //监听的内容，注意一定要从小到大输入
// 	"current": "xuanzhong" 						  //选中的样式
// });

function lifteffect(json){

var array=[];

for(var i =0; i<json.target.length;i++){
	var t = $(json.target[i]).offset().top;
	array.push(t);

}

function selected(index){
	$(json.control2).children().eq(index).addclass(json.current).siblings().removeclass(json.current);
}


$(window).on("scroll",check);

function check(){

	var wst = $(window).scrolltop();

	
	if(wst >= $(json.target[0]).offset().top-100){
		$(json.control1).fadein(500);
	}else{
		$(json.control1).fadeout(500);
	}

	var key =0;
	var flag = true;
	for(var i =0; i<array.length; i++){
		key++;
		if(flag){

			if(wst >= array[array.length-key]-300){
				var index = array.length-key;
				flag = false;
			}else{
				flag=true;
			}
			
		}
	}
	selected(index);
}

$(json.control2).children().on("click",function(){

		$(window).off("scroll");
		var index = $(this).index();
		selected(index);

		
		var flag = true;
		for(var i =0; i<array.length; i++){
		
			if(flag){
	
				if(index == i){
					$("html,body").stop().animate({
						"scrolltop": array[i]-50
					},500,function(){
						$(window).on("scroll",check);
					});
					flag = false;
				}else{
					flag=true;
				}
				
			}
		}
		
});



}