using System.Web;
    using System.Web.UI;
    using System.Web.UI.WebControls;
    using System.Data.SqlClient;
    using System.Data;
    using System;
    using System.Configuration;
    using System.Text;
    using System.Collections.Generic;
    using System.Linq;
    using System.Xml.Linq;

    public partial class Index : System.Web.UI.Page
    {

    protected void Page_Load(object sender, EventArgs e)
        {
        }

    protected void BtnLogin_Click(object sender, EventArgs e)
        {
            SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["Data Source=Server;Initial Catalog=DB;Integrated Security=True"].ConnectionString);
            conn.Open();
            string checkuser = "SELECT Username FROM USER WHERE Username='" + TextBoxUser.Text + "'";
            SqlCommand com = new SqlCommand(checkuser, conn);
            int temp = Convert.ToInt32(com.ExecuteScalar().ToString());
            conn.Close();
        if (temp == 1)
        {
            conn.Open();
            string checkPasswordQuery = "SELECT Password FROM USER WHERE Password= '" + TextBoxPassword.Text + "'";
            SqlCommand passCom = new SqlCommand(checkPasswordQuery, conn);
            string password = passCom.ExecuteScalar().ToString().Replace(" ", "");
            if (password == TextBoxPassword.Text)
            {
                Session["New"] = TextBoxUser.Text;
                Response.Redirect("~/main.aspx");
            }
            else
            {
                Response.Redirect("~/password_in.aspx");
            }
        }
        else
        {
            Response.Redirect("~/password_in.aspx");
        }
   }

    public class TextBoxUser
    {
        internal static string Text;
    }

    public class TextBoxPassword
    {
        internal static string Text;
    }
}