基于JavaScript实现图片点击弹出窗口而不是保存

<script>function picHook(pic){/*图片对象*/var imgs = document.getElementsByTagName("img");/*前景div*/var light = document.getElementById('light') || document.createElement("div");/*背景div*/var bg = document.getElementById('bg') || document.createElement("div");/*图片放大*/var s_pic = document.getElementById('s_pic') || document.createElement("img");/*css对象*/var css = document.createElement("style");/*css样式*/var csstext = '/.pic_bg{/position: absolute;/margin:0 auto; /top: 0%;/left: 0%;/width: 100%;/padding-bottom: 1000%;/background-color: black;/z-index:1001;/opacity:.80;/filter: alpha(opacity=80);/overflow:scroll;/}/.pic_div {/margin-bottom: auto;/position: fixed;/left:50%;/top:50%;/margin-left:-250px;/margin-top:-100px;/z-index:1002;/}';/*收集页面所有图片对象*/for(i=0; i<imgs.length;i++){imgs[i].setAttribute("onclick", "picHook(this)" );}css.type = "text/css";/*关闭图像*/if( !pic ){bg.style.display = light.style.display = "none";}/*ie兼容*/if(css.styleSheet){css.styleSheet.cssText = csstext;}else{css.appendChild(document.createTextNode(csstext));}s_pic.setAttribute("id", "s_pic");s_pic.setAttribute("src", pic.src);light.setAttribute("id", "light");light.setAttribute("class", "pic_div");light.style.display = 'block';light.appendChild(s_pic);bg.setAttribute("id", "bg");bg.setAttribute("class", "pic_bg");bg.setAttribute("onclick", "picHook()");bg.style.display = light.style.display;document.getElementsByTagName("head")[0].appendChild(css); document.body.appendChild(bg);document.body.appendChild(light);}</script>