How to Go From Form1 to Form2 in Windows Application

I have two forms, form1 and form2 and I have a button1 on form 1. Now, when I click on the button1, the page shall redirect to form2.

 

After clicking on the button.

 

private void btn_Click(object sender, EventArgs e)

{

     this.Hide();

     form2  a1 = new form2();

     a1.ShowDialog();

}