javascript 输入框提示列表效果

代码可以更简洁些，有更简便的方法欢迎贡献出来啊。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>输入框提示列表效果_脚本之家</title> <style type="text/css"> <!-- body{background:#fff} .Menu { position:relative; width:204px; height:127px; z-index:1; background: #FFF; border:1px solid #000; margin-top:-100px; display:none; } .Menu2 { position: absolute; left:0; top:0; width:100%; height:auto; overflow:hidden; z-index:1; } .Menu2 ul{margin:0;padding:0} .Menu2 ul li{width:100%;height:25px;line-height:25px;text-indent:15px; border-bottom:1px dashed #ccc;color:#666;cursor:pointer; change:expression( this.onmouseover=function(){ this.style.background="#F2F5EF"; }, this.onmouseout=function(){ this.style.background=""; } ) } input{width:200px} .form{width:200px;height:auto;} .form div{position:relative;top:0;left:0;margin-bottom:5px} #List1,#List2,#List3{left:0px;top:93px;} --> </style> <script type="text/javascript"> function showAndHide(obj,types){ var Layer=window.document.getElementById(obj); switch(types){ case "show": Layer.style.display="block"; break; case "hide": Layer.style.display="none"; } } function getValue(obj,str){ var input=window.document.getElementById(obj); input.value=str; } </script> </head> <body> Location：<input type="text" id="txt" name="txt" onClick="showAndHide('List1','show');" onblur="showAndHide('List1','hide');"> <!--列表1--> <ul> <li onmousedown="getValue('txt','中国CHINA');showAndHide('List1','hide');">中国CHINA</li> <li onmousedown="getValue('txt','美国USA');showAndHide('List1','hide');">美国USA</li> </ul> Sex：<input type="text" id="txt2" name="txt2" onClick="showAndHide('List2','show');" onblur="showAndHide('List2','hide');"> <!--列表2--> <ul> <li onmousedown="getValue('txt2','男Male');showAndHide('List2','hide');">男Male</li> <li onmousedown="getValue('txt2','女Female');showAndHide('List2','hide');">女Female</li> </ul> education：<input type="text" id="txt3" name="txt3" onClick="showAndHide('List3','show');" onblur="showAndHide('List3','hide');"> <!--列表3--> <ul> <li onmousedown="getValue('txt3','大专');showAndHide('List3','hide');">大专</li> <li onmousedown="getValue('txt3','本科');showAndHide('List3','hide');">本科</li> <li onmousedown="getValue('txt3','硕士');showAndHide('List3','hide');">硕士</li> <li onmousedown="getValue('txt3','本科');showAndHide('List3','hide');">本科</li> </ul> </body> </html>
[Ctrl+A 全选 注:如需引入外部Js需刷新才能执行]