Open URL from button

This is probably the easiest thing, but its still a problem for me!
I have a button I want to get to a website with.
I know its just to put the getURL() code, but it isnt just to write:
“getURL(http://www.example.com)” is it? It says something about getURL(url,window,method);. Whats the window and method?

Or simply, whats the code I need to write on the button I want to open “http://www.home.no/oyvindr” with? (I want to open it in a new window.)