Simple Action Bar ( press 1 button and back button )

i looked all action bar samples, but its some a little bit complicated i guess.

i dont know much fragmented style so i think with action bar its more like monotouch style,

is there a simple like press back or options img on action bar?

when i check samples its shows me only message box but i get stuck at what if when i press back or other button process?

public override bool OnCreateOptionsMenu (IMenu menu)
    {}

menu. image or something?