怎么只有登陆界面呢？输入用户名和密码后点击没反应啊

下面的是代码：
<%@ page contentType="text/html;charset=gb2312" language="java"%>
<%@ page import="java.sql.*,java.io.*" %>
<%
String username= request.getParameter("username");
String password= request.getParameter("password");
  Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
  Connection con=DriverManager.getConnection("jdbc:odbc:xumen","sheng","123456");
  Statement stmt=con.createStatement();
  String isCorrect="select * from tb_user where username='"+username+"'and password='"+password+"'";
  ResultSet rs=stmt.executeQuery(isCorrect);
  if(!rs.next())
  {
   response.sendRedirect("login.html");
   rs.close();
   stmt.close();
   con.close();
   }
   else if(rs.getString("isCheck").equals("0"))
   {
   session.setAttribute("username",rs.getString("username"));
   session.setAttribute("password",rs.getString("password"));
   session.setAttribute("isCheck",rs.getString("isCheck"));
   try
   {
   stmt.executeQuery("update tb_user set isCheck='"+1+"'where username='"+username+"'");
   stmt.close();
   con.close();
   rs.close();
   }
   catch(Exception e)
   {
   e.printStackTrace();
   }
   response.sendRedirect("index.html");
   }
   else
   {response.sendRedirect("watch.jsp");
    stmt.close();
    con.close();
    rs.close();
    }
  
%>