今天进行代码的优化问题，对查询的语句进行更改。
进行金额的保留小数。
out.print(String.format("%.2f", jiage));
<!DOCTYPE HTML>
<html>
<head>
<title>登录界面</title>
<meta charset="utf-8">
<meta http-equiv="pragma" content="no-cache">
<meta http-equiv="cache-control" content="no-cache">
<meta http-equiv="expires" content="0">
<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
<meta http-equiv="description" content="This is my page">
<link rel="stylesheet" type="text/css" href="css.css" />
</head>
<body>
<form name="form1" action="" method="post">
<h1>供货商登录</h1>
<input class=input_1 id=username size=15 name="username" placeholder=用户名><br />
<input class=input_1 id=password type=text size=15 name="password" placeholder=密码><br />
<br/>
<input class=input_3 type="button" onclick="login()" value="登录" />
<input class=input_3 type="button" onclick=document.form1.reset() value="重置" />
<input class=input_3 type="button" onclick="zhucea()" value="注册" />
</form>
<script type="text/javascript" src="script.js"></script>
</body>
</html>