private void button4_Click(object sender, EventArgs e)
        {
            this.Hide();
            Main_Menu mn = new Main_Menu();

            mn.ShowDialog();
        }
        private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(@"Server = KHALID;Database=Hospital;Integrated Security = true");

            if (user_txt.Text == "" || pass_txt.Text == "")
            {
                MessageBox.Show("Please Provide User name and Password");
                return;
            }

            try
            {
                // SqlConnection con = new SqlConnection(cs);

                SqlCommand cmd = new SqlCommand("select * from Login where USERNAME = '******' and PASSWORD = '******'", con);
                cmd.Parameters.AddWithValue("@userid", user_txt.Text);
                cmd.Parameters.AddWithValue("@password", pass_txt.Text);
                con.Open();
                SqlDataAdapter adapt = new SqlDataAdapter(cmd);
                DataSet        ds    = new DataSet();
                adapt.Fill(ds);

                con.Close();
                int count = ds.Tables[0].Rows.Count;
                if (count == 1)
                {
                    MessageBox.Show("Successfully LogIn");
                    this.Hide();
                    Main_Menu mn = new Main_Menu();
                    mn.Show();
                }


                else
                {
                    MessageBox.Show("Login Failed !! ");
                }
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }