CSHARP

c# close 1 form open another form

		this.Hide();//Hide the 'current' form, i.e frm_form1 
        //show another form ( frm_form2 )   
        frm_form2 frm = new frm_form2();
        frm.ShowDialog();
        //Close the form.(frm_form1)
        this.Close();

c# open a new form and close current

{
    this.Hide();
    Form1 f1 = new Form1();
    f1.ShowDialog();
    this.Close();
}