Problem with Form1_GotFocus event

Question

Newbie here :D

I have aplication with 2 forms (form1, form2). First form opens the second(form2). When form2 is closed i need to activate gotfocus event on form1. I've tried something like this:

 this.GotFocus += new System.EventHandler(this.Form1_GotFocus);
 private void Form1_GotFocus(object sender, EventArgs e) 
 {
            MessageBox.Show("wazaa");
 }

If my aproach is no good pls tell me how to activate something like messagebox on form1 when second form close
Sry for my bad english and pls help if u can