C# ToolStripMenuItem disabled depending on the user account

 private void button1_Click(object sender, EventArgs e)
        {
            SqlConnection con = new SqlConnection(@"Data Source=YOUMANI\YOUMANI;Initial Catalog=GestPharma;Integrated Security=True");
            SqlDataAdapter da = new SqlDataAdapter("select count(*) from personnel where username ='" + textBox1.Text + "'and password='" + textBox2.Text + "' and role = '"+ comboBox1.Text+"'", con);
            DataTable dt = new DataTable();
            da.Fill(dt);
            if (dt.Rows[0][0].ToString() == "1")
            {
                /*this.Hide();
                MenuAdmin ms = new MenuAdmin();
                ms.Show();*/
                 SqlDataAdapter da1 = new SqlDataAdapter("select role from personnel where username ='" + textBox1.Text + "'and password='" + textBox2.Text + "'", con);
            DataTable dt1 = new DataTable();
            da1.Fill(dt1);
            if (dt1.Rows[0][0].ToString() == "Admin")
                {
                    this.Hide();
                    MenuAdmin ma = new MenuAdmin();
                    ma.Show();
                }

            else
            {
                MessageBox.Show("Please check your Username And Password");
            }

            if (dt1.Rows[0][0].ToString() == "User")
                {
                    this.Hide();
                    MenuUser mu = new MenuUser();
                    mu.Show();
                }
              
            }
            else
            {
                MessageBox.Show("Please check your Username And Password");
            }

           

        }