member.jsp //session限制访问页
<%
String url = ""
if(session.getAttribute("username")==null)
{
url = myRedirect.dealurl(request);//记录当前地址和请求参数，dealurl将实际url处理了避免和要请求url有干扰,因为会有& 字符
response.sendRedirect("weblogin.jsp?url＝"+url) ;//重定向到登录页面
}
%>
------------------------------------------------
weblogin.jsp
<%
String url = request.getParameter("url");
String userid =request.getParameter("userid");
String password =request.getParameter("password");
if(userid!=null) //如果是登录提交执行下面代码
{
if(登录成功)
{
session.setAttribute("userid",userid);
out.println("<script>alert('登录成功，谢谢光临');self.location.href='"+myRedirect.geturl(url)+"';</script>");//转向到首次请求的url，.geturl(url)是把转化过的地址转化回来变成真实url.
}else{
out.println("<script>alert('用户名或密码错误');history.back();</script>");
}
}else{//如果不是登录提交显示现面登录界面
%>
<table width="311" height="162" border="0" align="center" cellpadding="0" cellspacing="0">
<tr>
<td width="311" height="162" align="center"> 您还没有登录，请先登录<br>
<table width="155" border="0" cellpadding="0" cellspacing="5" class="font12">
<form name="loginfrm" action="weblogin.jsp" method="post" id="loginfrm" onSubmit="return checkfrm();">
<tr>
<td width="41" height="33" valign="bottom">帐 号：</td>
<td width="99" valign="bottom"><input name="user
