function zoom(mask,bigimg,smallimg){this.bigimg=bigimg;this.smallimg=smallimg;this.mask=mask}zoom.prototype={init:function(){var that=this;this.smallimgClick();this.maskClick();this.mouseWheel()},smallimgClick:function(){var that=this;$("."+that.smallimg).click(function(){$("."+that.bigimg).css({height:$("."+that.smallimg).height()*3,width:$("."+that.smallimg).width()*3});$("."+that.mask).fadeIn();$("."+that.bigimg).attr("src",$(this).attr("src")).fadeIn()})},maskClick:function(){var that=this;$("."+that.mask).click(function(){$("."+that.bigimg).fadeOut();$("."+that.mask).fadeOut()})},mouseWheel:function(){function mousewheel(obj,upfun,downfun){if(document.attachEvent){obj.attachEvent("onmousewheel",scrollFn)}else{if(document.addEventListener){obj.addEventListener("mousewheel",scrollFn,false);obj.addEventListener("DOMMouseScroll",scrollFn,false)}}function scrollFn(e){var ev=e||window.event;var dir=ev.wheelDelta||ev.detail;if(ev.preventDefault){ev.preventDefault()}else{ev.returnValue=false}if(dir==-3||dir==120){upfun()}else{downfun()}}}var that=this;mousewheel($("."+that.bigimg)[0],function(){if($("."+that.bigimg).innerWidth()>$("body").width()-20){alert("不能再放大了");return}if($("."+that.bigimg).innerHeight()>$("body").height()-50){alert("不能再放大");return}var zoomHeight=$("."+that.bigimg).innerHeight()*1.03;var zoomWidth=$("."+that.bigimg).innerWidth()*1.03;$("."+that.bigimg).css({height:zoomHeight+"px",width:zoomWidth+"px"})},function(){if($("."+that.bigimg).innerWidth()<100){alert("不能再缩小了哦！");return}if($("."+that.bigimg).innerHeight()<100){alert("不能再缩小了哦！");return}var zoomHeight=$("."+that.bigimg).innerHeight()/1.03;var zoomWidth=$("."+that.bigimg).innerWidth()/1.03;$("."+that.bigimg).css({height:zoomHeight+"px",width:zoomWidth+"px"})})}};