<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title> New Document </title>
<meta name="Generator" content="EditPlus">
<meta name="Author" content="">
<meta name="Keywords" content="">
<meta name="Description" content="">
</head>
<script language="JavaScript">
function isreadonly(){
var obj = document.getElementById("username");
obj.setAttribute("readOnly",true);
}
function readwrite(){
var obj = document.getElementById("username");
obj.setAttribute("readOnly",false);
}
</script>
<body>
<form name="addform" id="addform" method="post" action="">
<input type="text" id="username" name="username" >
<input type="button" name="只读" value="只读" onclick="isreadonly();">
<input type="button" name="可写" value="可写" onclick="readwrite();">
</form>
</body>
</html>