<html>
<head>
<meta http-equiv="content-Type" content="text/html;charset=gb2312">
<title>一個和論壇驗證碼相似的功能_/</title>
<style type="text/css">
.header
{
width:58px;
height:23px;
background-color:#009999;
font-size:14px;
color:red;
display:none;
}
</style>
</head>
<script language="javascript">
<!--
function dian()
{
if( txt.value="")
{
document.getElementsByTagName("span")[0].style.display="none";
}
else
{
document.getElementsByTagName("span")[0].style.display="block";
}
}
-->
</script>
<body>
<span class="header">6253</span>
<input type="text" size="20" id="txt" value="" onClick="dian()">
</body>
</html>
