Code for creating new popup window from a click button

I need code in c# or in vb for creating a popup window so that i use this popup window for adding any chat messenger code.. can anyone help me please.. its urgent.
thanks.

 

Have a try:

private void Button_OnClick(object sender, EventArgs e)
{
FormTest form = new FormTest();
form.ShowDialog();
this.Refresh();
}