try
        {
            if (!(Username_Text.Text == string.Empty))
            {
                if (!(Password_Text.Text == string.Empty))
                {
                    SqlConnection connection = new SqlConnection("Data Source=ICSD-DB\\ICSDMSSQLSRV;Initial Catalog=icsd14063;Integrated Security=True");
                    String sqlString = "select * from RegisterUsers where username = '" + Username_Text.Text + "'and pass = '" + GetStringSha256Hash(Password_Text.Text) + "'";
                    connection.Open();
                    SqlCommand command = new SqlCommand(sqlString, connection);
                    SqlDataReader dbr;
                    dbr = command.ExecuteReader();
                    int count = 0;
                    while (dbr.Read())
                    {
                        count = count + 1;
                    }
                    if (count == 1)
                    {
                        MessageBox.Text = ("Username and password is correct.");
                        Session["Set_Visible"] = "true";
                        Response.Redirect("Home.aspx?number1=" + Username_Text.Text);
                    }
                    else if (count > 1)
                    {
                        MessageBox.Text = ("Username and password incorrect.");
                    }
                    else
                    {
                        MessageBox.Text = ("Username and password incorrect.");
                    }
                }
                else
                {
                    MessageBox.Text = ("Password empty.");
                }
            }
            else
            {
                MessageBox.Text = ("Username empty.");
            }
        }
        catch (Exception ex)
        {
            MessageBox.Text = ex.ToString();
        }