<!doctype html> <html> <head> <meta charset="utf-8"> <title>无标题文档</title> <script> window.onload = function () { var oa = document.getElementsByTagName('a'); var oul = document.getElementById('ul1'); var ali = oul.getElementsByTagName('li'); for(var i = 0; i < oa.length; i++) { oa[i].onclick = function () { if(mj(this.innerHTML)) { var oli = document.createElement('li'); oli.innerHTML = this.innerHTML; if(!ali[0]) { oul.appendChild(oli); } else { oul.insertBefore(oli,ali[0]); } } else { mj2(this.innerHTML); } } } function mj(text) { for(var i = 0; i < ali.length; i++) { if(text == ali[i].innerHTML) { return false; } } return true; }; function mj2(text) { for(var i = 0; i < ali.length; i++ ) { if(text == ali[i].innerHTML) { oul.insertBefore(ali[i],ali[0]); } } } } </script> </head> <body> <a href="javascript:;">北京</a> <a href="javascript:;">上海</a> <a href="javascript:;">西安</a> <a href="javascript:;">深圳</a> <a href="javascript:;">香港</a> <a href="javascript:;">杭州</a> <a href="javascript:;">澳门</a> </ul> <ul id="ul1"></ul> </body> </html>