C# CODE

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;

public partial class _Default : System.Web.UI.Page 
{
	protected bool ValidateUser(string userName, string passWord)
	{

		SqlConnection Conn;

		SqlCommand cmd;

		string lookupPassword = null;

		try
		{

			Conn = new SqlConnection("Data Source=xxx;User ID=xxx;Password=xxxx");

			Conn.Open();


			cmd = new SqlCommand("Select pwd from users where uname = '@userName'", Conn);

			cmd.Parameters.Add("@userName");

			cmd.Parameters["@userName"].Value = userName;


			lookupPassword = (string)cmd.ExecuteScalar();


			cmd.Dispose();

			Conn.Dispose();

		}

		catch (Exception ex)
		{


			System.Diagnostics.Trace.WriteLine("[ValidateUser] Exception ");

		}

		if (null == lookupPassword)
		{


			return false;

		}


		return (0 == string.Compare(lookupPassword, passWord, false));

	}
	
}

.aspx CODE

private void cmdLogin_ServerClick(object sender, System.EventArgs e)
    {
        if (ValidateUser(txtUserName.Value, txtUserPass.Value))
        
            FormsAuthentication.RedirectFromLoginPage(txtUserName.Value,
			chkPersistCookie.Checked);
            
        
        else
            Response.Redirect("logon.aspx", true);
    }

Data Source=SERVERNAME;Initial Catalog=DATABASENAME;UID=USERNAME;PWD=PASSWORD