validation problem using jsp,servlets,ms-access db

thanks in advance,please help me. I am working on a project wherein for now i have to prepare a login page which is to be validated with the .I know to code the database connectivity and validation in jsp but if i use a servlet for db connection and validation,i dont know how to give link to the particular servlet page through jsp as well as to get the parameters from servlets and how to use it in other jsp as well.servlet for connecivity is given below

This is the code in

%@page contentType="text/html"%> 
<%@page language ="java" %> 
<%@page import="java.sql.*,javax.sql.*,javax.naming.*,java.io.*,
java.util.*" %>
 
 <html> 
<head> 
<title>JSP Page</title> 
</head>
 <body> 
 
 <%
            String userid = request.getParameter("userid");
            String password = request.getParameter("pass");
 
            try
            {
 
                Connection connection = null;
                Statement st = null;
                ResultSet rs = null;
                Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
                connection = DriverManager.getConnection("jdbc:odbc:employee_dat");
                st = connection.createStatement();
 
 
 
                rs = st.executeQuery("select userid from user where userid='" + userid + "' and password='" + password + "'");
                out.println("Valid==" + rs);
                if (rs.next())
                {
                    String UserID = rs.getString("userid");
                    out.println("Valid user=" + UserID);
        %>
        <jsp:forward page="/main.jsp" />            
        
        <%
          } else
          {
              out.println("Invalid user");
 
        %>           
        <jsp:forward page="/AccessDenied.jsp" />
        <%
                }
                rs.close();
            } catch (Exception ex)
            {
                out.println(ex.getMessage());
 
 
 
                out.println("Unable to connect to database.");
            }
        %>
        
    </body> 
</html>

You can use RequestDispatcher to forward to that particular jsp

along with this code can i do the validation also in the servlet.please suggest me.if possible give me a clear view as to how to do it.
thanks in advance.