check user is admin or not?

Hi guys,
I have budget form and i want to display that only when user is admin.
I have "users" table and userID is primary key. there is field "role".
And role column contain different name like approver,user,admin and etc...
now I want that if user role is admin then budget page should display only.

I have following code for login.
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using System;
using System.Data;
using System.Configuration;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}

protected void Login1_Authenticate(object sender, AuthenticateEventArgs e)
{
try

{

string uname = Login1.UserName.Trim(); //Get the username from the control

string password = Login1.Password.Trim(); //get the Password from the control
Session.Add("username",uname);

bool flag = AuthenticateUser(uname, password);

if (flag == true)

{

e.Authenticated = true;

Login1.DestinationPageUrl = "disclamer.aspx";

}

else

e.Authenticated = false;

}

catch (Exception)

{

e.Authenticated = false;

}
}
private bool AuthenticateUser(string uname, string password)

{

bool bflag = false;

string connString = @"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\fpd.mdf ;Integrated Security=True;User Instance=True";

string strSQL = "select * from users where userID ='" + uname + "' AND password ='" + password + "'";

DataSet userDS = new DataSet();

SqlConnection m_conn;

SqlDataAdapter m_dataAdapter;

SqlCommand m_Command;

try

{

m_conn = new SqlConnection(connString);

m_conn.Open();

m_dataAdapter = new SqlDataAdapter(strSQL, m_conn);

m_dataAdapter.Fill(userDS);

m_conn.Close();

}

catch (Exception ex)

{

userDS = null;

}

if (userDS != null)

{

if(userDS.Tables[0].Rows.Count > 0)

bflag = true;

}

return bflag;

}
}
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So can anybody give me idea please?

Thanks a lot.