Testingsqllogin

using System;
using System.Data.SqlClient;
using System.Text;
namespace SqlLoginSystem
{
    class Program{
        SqlConnectionString conndata = new SqlConnectionString();
        SqlConnection conn;
        SqlCommand cmd;
        public string sessionID=ReqdFromFile???;
        public string username=null;
        public string userpass=null;
        int alg=1;

        public void Auth(){
            this.conndata.id="dbuser";
            this.conndata.pass="dbuserpass";
            this["Database"]="StudentAppTest";
            this.conndata.host="host";
            conn=new SqlConnection(conndata);
            try{
                conn.Open();
            }
            catch(SqlExeption e){
                status.Caption="Server Error!\nPlease try later!";
            }
            finaly{
                conn.Close();
            }

        }

        void Main(){
            Auth();
            cmd =new SqlCommand("SELECT count(*) as cnt FROM Users WHERE UserName=@usr and LoggedIn=@alg and sessionID=@sID", conn);
            cmd.Parameters.Clear();
            cmd.Parameters.AddWithValue("@usr",username);
            cmd.Parameters.AddWithValue("@alg",alg);
            cmd.Parameters.AddWithValue("@sID",sessionID);
            conn.Open();
            if(cmd.ExecuteScalar().ToString()=="1"){
                conn.Close();
                MainWindows success = new MainWindow();
                this.Close();
                main.Show();
            }
            else conn.Close();
        }

        private void login_button_Clicked(){
            Auth();
            cmd =new SqlCommand("SELECT count(*) as cnt FROM Users WHERE UserName=@usr and UserPass=@pass", conn);
            cmd.Parameters.Clear();
            cmd.Parameters.AddWithValue("@usr",username);
            cmd.Parameters.AddWithValue("@pass", userpass);
            conn.Open();
            if(cmd.ExecuteScalar().ToString()=="1"){
                conn.Close();
                private Guid gsID = new System.Guid.NewGuid();
                cmd. new SqlCommand("INSERT INTO Users ROW sID values('@sgID') WHERE UserName=@usr", conn);
                cmd.Parameters.Clear();
                cmd.Parameters.Add("@gsID",SqlDbType="uniqueidentifier").Value=gsID;
                cmd.Parameters.AddWithValue("@usr", username);
                conn.Open();
                conn.ExecuteReader();
                conn.Close();
                cmd = new SqlCommand("SELECT count(*) AS cnt FROM Users WHERE UserName=@usr and sID=@sgID", conn)
                cmd.Parameters.Clear();
                cmd.Parameters.Add("@gsID",SqlDbType="uniqueidentifier").Value=gsID;
                cmd.Parameters.AddWithValue("@usr", username);
                conn.Open();
                if(cmd.ExecuteScalar().ToString()=="1"){
                    conn.Close();
                    StoreIntoFile???(gsID.ToString());
                    MainWindows success = new MainWindow();
                    this.Close();
                    success.Show();
                }
                else{
                    conn.Close();
                }
            }
            else
            {
                status.Caption="Invalid logincredentials!";
                conn.Close();
            }

        }

    }

}