index.jsp
<head>
<title>My JSP 'index.jsp' starting page</title>
<script type="text/javascript">
function myCheck()
{
if(form1.name.value=="")
{
alert("请输入用户名!");
}
if(form1.password.value=="")
{
alert("请输入密码！");
}
if(form1.check.value=="")
{
alert("请输入验证码！");
}
if(form1.check.value!=form1.checkAnswer.value)
{
alert("验证码不正确！");
}
}
</script>
</head>
<body>
<form action="check.jsp" method="post" name="form1">
<table align="center">
<tr>
<td>用户名：</td>
<td><input type="text" name="name" onMouseOut="this.background='green';">
</td>
</tr>
<tr>
<td>密 码：</td>
<td><input type="password" name="password">
</td>
</tr>
<tr>
<td>验证码：</td>
<td>
<input type="text" name="check">
<%int intmethod=(int)(Math.random()*10);
int intmethod2=(int)(Math.random()*10);
int intmethod3=(int)(Math.random()*10);
int intmethod4=(int)(Math.random()*10);
String intsum=intmethod+""+intmethod2+""+intmethod3+""+intmethod4;%>
<input type="hidden" name="checkAnswer" value="<%=intsum %>">
</td>
<td>
<span ><img src="number/<%=intmethod %>.jpg" height="20px">
<img src="number/<%=intmethod2 %>.jpg" height="20px">
<img src="number/<%=intmethod3 %>.jpg" height="20px">
<img src="number/<%=intmethod4 %>.jpg" height="20px">
</span>
</td>
</tr>
<tr>
<td></td>
<td>
<input type="submit" value="提交" name="submit" onClick="myCheck()">
<input type="reset" value="重置" name="submit2">
</td>
</tr>
</table>
</form>
</body>
check.jsp
<body>
<%
String name=request.getParameter("name");
String password=request.getParameter("password");
String message;
if(name.equals("min")&&(password.equals("123456")))
{
message="欢迎登陆系统";