//javascript document
function chinaz(){
	this.init();
}
chinaz.prototype = {
	constructor: chinaz,
	init: function(){		
		this._initbacktop();
	},	
	_initbacktop: function(){
		var $backtop = this.$backtop = $('<div class="cbbfixed">'+
						'<a class="cweixin cbbtn"">'+
							'<span class="weixin-icon"></span><div></div>'+
						'</a>'+
						'<a class="gotop cbbtn">'+
							'<span class="up-icon"></span>'+
						'</a>'+
					'</div>');
		$('body').append($backtop);
		
		$backtop.click(function(){
			$("html, body").animate({
				scrolltop: 0
			}, 120);
		});

		var timmer = null;
		$(window).bind("scroll",function() {
            var d = $(document).scrolltop(),
            e = $(window).height();
            0 < d ? $backtop.css("bottom", "10px") : $backtop.css("bottom", "-90px");
			cleartimeout(timmer);
			timmer = settimeout(function() {
                cleartimeout(timmer)
            },100);
	   });
	}
	
}
var chinaz = new chinaz();