Validating logon... prb

Question

hi...
something wrong with this code?
its a log in validation, if the user detials dont exits it should output something otherwise go to another link... depending on the resultset,
but it doesnt seem to work if the user detials are invalid, i.e when the resulset does not return antyihng ==null.... it goes to a blank page... but not with the output....
method
public ResultSet validUser(String email, String password)
         try
               String query = "SELECT * FROM Users WHERE email = '" +  email + "' AND password = '" + password + "'";
             Statement stmt = conn.createStatement();
             rs = stmt.executeQuery(query);
         catch ( SQLException sqle )
               errorMsg = errorMsg + "\n" + "Error: SQLException " + sqle.getMessage();
         catch (Exception e)
               errorMsg = errorMsg + "\n" + "Error: General: " +e.getMessage();
          return rs;
JSP
String email = request.getParameter("email");
     String password = request.getParameter("password");
     String type = null;
     logon.connect();
     ResultSet rs = logon.validUser(email, password);
     if (rs == null)
     { %>
</p>
         <p>Sorry please Enter your own Email and registration number, the system does not recognise your email or password
          <a href="frontPage.htm">click Here to go Back</a>
           <%
     if (rs.first())
          type = rs.getString(3);
     if (type.equals("student"))
     { %>
          <jsp:forward page="studentMain.jsp"/>
       <%
     else if (type.equals("teacher"))
     {     %>
          <jsp:forward page="teacherMain.jsp"/>
         <p>
           <%
     logon.disconnect();
     %>
<%= logon.getError() %>

Answer 1

in that code, it looks like if rs is null, you are still attempting to call first or other methods on it... Personally, I wouldn't return a result set from the login method. I would return null if it's invalid and if it's a valid login, create an object (some bean class) that contains the user information and store that in the session, that way you always have it from then on elsewhere.