Login validation and redirection - asp.net

Question

I am trying to implement a Login validation using C# 2005 in ASP.net 2.0 web application. The SQL Server database contains a table named "UserList" with columns LoginId, Password and Role. The Login webform should authenticate the LoginId and password and depending upon the Role assigned to that user/visitor should redirect to a specific webform with a pre-defined menu options. The role might be Admin, DEO, Accounts or Member. How should I implement it? I have tried the following:
protected void Login1_Authenticate(object sender, AuthenticateEventArgs e)
{
try
{
string uname = Login1.UserName.Trim();
string password = Login1.Password.Trim();
int flag = AuthenticateUser(uname, password);
if (flag == 1)
{
e.Authenticated = true;
Login1.DestinationPageUrl = "~/MenuAdmin.aspx";
}
else if (flag == 2)
{
e.Authenticated = true;
Login1.DestinationPageUrl = "~/MenuDEO.aspx";
}
else if (flag == 3)
{
e.Authenticated = true;
Login1.DestinationPageUrl = "~/MenuAccts.aspx";
}
else if (flag == 4)
{
e.Authenticated = true;
Login1.DestinationPageUrl = "~/MenuMember.aspx";
}
else
{
e.Authenticated = false;
}
}
catch (Exception)
{
e.Authenticated = false;
}
}
private int AuthenticateUser(string uname, string password)
{
int bflag = 0;
string connString = ConfigurationManager.ConnectionStrings["LoginDemoConnString"].ConnectionString;
string strSQL = "Select * FROM UserList where ULoginId ='" + uname + "' AND UPassword ='" + password + "'";
DataTable dt = new DataTable();
SqlConnection m_conn;
SqlDataAdapter m_dataAdapter;
try
{
m_conn = new SqlConnection(connString);
m_conn.Open();
m_dataAdapter = new SqlDataAdapter(strSQL, m_conn);
m_dataAdapter.Fill(dt);
m_conn.Close();
}
catch (Exception ex)
{
dt = null;
}
finally
{
//m_conn.Close();
}
if (dt.Rows.Count > 0)
{
if (dt.Rows[0][3].ToString() == "Administrator")
bflag = 1;
else if (dt.Rows[0][3].ToString() == "DEO")
bflag = 2;
else if (dt.Rows[0][3].ToString() == "Accts")
bflag = 3;
else
bflag = 4;
}
return bflag;
}

Answer 1

Well first of all I guess each role in the sql table has id so you can get rid of the ifs in the AuthenticateUser and just return the id. Or you can also return the actual role and just do something with this data in the Login1_Authenticate function.
Now you can also get rid of the ifs in the Login1_Authenticate function if you will use dictionary where the key is role and value is pageURL so you can just write something like that:
int flag = AuthenticateUser();
Login1.DestinationPageUrl = roles.ElementAt(flag).Value;