//If click on specific Menu Strip item then show that clicked form and hide this one.
        private void toolStripMenuItem1_Click(object sender, EventArgs e)
        {
            this.Hide();
            admin_main am = new admin_main();

            am.Show();
        }
 //Admin Login authenticator
 private void button2_Click(object sender, EventArgs e)
 {
     //if username and password is "admin", then it logins as admin
     if (textBox3.Text == "admin" && textBox4.Text == "admin")
     {
         MessageBox.Show("Login Successful.");
         this.Hide();
         admin_main mn = new admin_main();
         mn.Show();
     }
     else
     {
         MessageBox.Show("Error! Please Check your Username or Password.");
     }
 }