like this?<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3c.org/TR/1999/REC-html401-19991224/loose.dtd">
<HTML xmlns="http://www.w3.org/1999/xhtml"><HEAD>
<TITLE></TITLE>
<META http-equiv=Content-Type content="text/html; charset=gb2312"><META content="MSHTML 6.00.2900.5512" name=GENERATOR></HEAD>
<BODY>
<style>
div {float:left;margin:2px;padding:2px}
*{font-size:12px;}
#username_info{width:300px;border:1px #eee solid;}
.username_info{border:1px #f00 solid;}
</style>
<DIV class=Hint>会员名:<INPUT id=username tabIndex=1 size=24 onblur=changcss(0) onfocus=changcss(1)></DIV> 
<DIV id=username_info>
  5-20个字符推荐使用中文会员名。一旦注册成功会员名不能修改。
</DIV>
<script language="javascript">
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var tmp
function changcss(k){
var obj=document.getElementById("username_info")
if (k==1){
tmp=obj.innerHTML
obj.style.borderColor="#f00"
obj.innerHTML="<img src='http://s.vdoing.com/icon/vd02.gif'>"+tmp
}
else{
obj.style.borderColor="#eee"
obj.innerHTML=tmp
}}
//-->
</script>
</BODY></HTML>