Unable to get the errorlogin.jsp to run correctly in a servlet.

Question

I am attempting to read the users input using jsp and run the servlet LoginServlet to cross check the database to see if that are in the database. The problem i am having is that i can get the login working but am unable to get the errorlogin to run if the details are incorrect. Can anyone see where i have gone wrong? Thanks!
package Login;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
public class LoginServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        try {
            try {
                Connection con = DBConnect.DbConnection.getConnection();
                Statement st = con.createStatement();
                String user = request.getParameter("t1");
                String pass = request.getParameter("t2");
                String strSQL = "SELECT username, password FROM users "
                        + "WHERE username = '" + user + "' "
                        + "AND password = '" + pass + "'";
                ResultSet rs = st.executeQuery(strSQL);
                String username, password;
                HttpSession session = request.getSession();
                while (rs.next()) {
                    username = rs.getString("username");
                    password = rs.getString("password");
                    if (user.equals(username) && pass.equals(password)) {
                        response.sendRedirect("next.jsp");
                    } else {
                        response.sendRedirect("errorlogin.jsp");
            } catch (ClassNotFoundException cnfe) {
                cnfe.getMessage();
        } catch (SQLException sqle) {
            sqle.getMessage();
}

Answer 1

How do You ensure that an exception is raised? Do You see any info in log files?
Not sure if this helps but try:
    response.sendRedirect(request.getConextPath()+"/errorlogin.jsp");In this case errorlogin.jsp should be put on the same level as WEB-INF directory is.