protected void logInButton_Click(object sender, EventArgs e)
        {
            LogIn userLogIn = new LogIn();

            userLogIn.CenterCode = centerCodeTextBox.Text;
            userLogIn.Password   = passwordTextBox.Text;
            int msg = centerManager.CompareCenterCodeAndPassword(userLogIn);

            if (msg == 1)
            {
                Session["User"] = userLogIn;
                Response.Redirect("~/UI/index.aspx");
            }
            else if (msg == 0)
            {
                messageLabel.Text = "Center code does not found";
            }
            else if (msg == -1)
            {
                messageLabel.Text = "Password does not match";
            }
            else
            {
                messageLabel.Text = "Enter Center code & Password Correctly";
            }
        }