Response to: Regarding Windows Form opening and closing

Revision 2
Take three forms

Formmain, Formfirst,Formsecond

public partial class FormMain : Form
    {
        public FormMain()
        {
            InitializeComponent();
            FormFirst frs = new FormFirst();
            frs.Show();
        }

        private void FormMain_Load(object sender, EventArgs e)
        {

        }
    }

In the Formfirst ok button click write below

public partial class FormFirst : Form
   {
       public FormFirst()
       {
           InitializeComponent();
       }
Below is the button click of formfirst
       private void button1_Click(object sender, EventArgs e)
       {
           FormSecond fs = new FormSecond ();
           fs.Show();
           this.Hide();

       }
   }