Notes/Domino 6 and 7 Forum : Domino /JSP tag

I have a login and dologin page when the user enter the a wrong password/username i want to come back to the login page. now it goes to the home .jsp page. but on the server console i get invalid usernae and password notes ecxeption error . can anyone help me?/

Login Page
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<HTML>
<HEAD>

<%@ taglib uri="/WEB-INF/domutil.tld" prefix="domutil" %>
<%@ page
language="java"
contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"
%>
<TITLE>Log In</TITLE>
</HEAD>
<BODY>
<form method="POST" action="index.jsp?link=Discussion/doLogin.jsp">

<domutil:if>
<domutil:condition debug="true" onfailure="exception">
<%= request.getParameter("lf") != null%>
</domutil:condition>
<left><font=red><b>Login Failure!</b></font></left>
<p>
</domutil:if>

<domutil:if>
<domutil:condition>
<%= request.getParameter("ar") != null%>
</domutil:condition>
<center><b>Authorization Required. Please Log In.</b></center>
<p>
</domutil:if>

<TABLE border="0">
<TBODY>
<TR>
<TD>Username:</TD>
<TD><input type="text" name="username"></TD>
</TR>
<TR>
<TD>Password:</TD>
<TD><input type="password" name="password"></TD>
</TR>
</TBODY>
</TABLE>
<input type="submit" value="Log In">
</form>
</BODY>
</HTML>

doloin page:

<% try {
String username = request.getParameter("username");
System.out.println("username:" + username);
String password = request.getParameter("password");
System.out.println("password:" + password);

%>

<domino:db host="" dbname="Table"
dbserver="Test"
user="<%=username%>"
password="<%=password%>">

<% // Store the username into session context
session.setAttribute("l_fullname", request.getParameter("username"));
session.setAttribute("l_user", request.getParameter("username"));
session.setAttribute("l_pw", request.getParameter("password"));
session.setAttribute("l_admin", "0");
%>

<domino:ifdbrole name="Admin">
<% session.setAttribute("l_admin", "1"); %>
</domino:ifdbrole>

</domino:db>

<%
response.sendRedirect("index.jsp/home.jsp");

} catch (Exception e) {
// flush current login info
session.setAttribute("l_user", null);
session.setAttribute("l_pw", null);
session.setAttribute("l_admin", null);
response.sendRedirect("login.jsp?lf=1");

}
%>