<table width="300" border="0" cellspacing="0" cellpadding="0">
    <form name="form1" method="post" action="login.jsp">
    <tr>
      <td>用戶名</td>
      <td><input type="text" name="username"></td>
    </tr>
    <tr>
      <td>密碼</td>
      <td><input type="text" name="password"></td>
    </tr>
    <tr>
      <td><input type="radio" name="radio" value="em" checked>
      普通用戶</td>
      <td><input type="radio" name="radio" value="admin">
      管理員</td>
    </tr>
    <tr>
      <td><input name="logon" type="button" id="logon" value="登陸" onClick="check()"></td>
      <td><input name="myreset" type="reset" id="myreset" value="取消"></td>
    </tr>
   </form>
  </table>
  <script language="javascript">
    function check(){
	   if(form1.username.value==0){
	     alert("請輸入用戶名");form1.username.focus();return;
	   }
	   if(form1.password.value==0){
	     alert("請輸入密碼");form1.password.focus();return;
	   }
          form2.
          form1.submit();
	}
  </script>
 <%
    String aa=(String)request.getParameter("radio");
    String name=(String)request.getParameter("name");
    String password=(String)request.getParameter("password");
    if(aa.equals("em")){
 %>
<form name="form2" method="post" action="em">
  <input type="hidden" name="id" value=name>
  <input type="password" name="password" value=password>
</form>
<%}else if(aa.equals("admin")){%>
<form name="form2" method="post" action="em">
  <input type="hidden" name="name" value=name>
  <input type="password" name="password" value=password>
</form>
<%}%>