>I have seen that in most of the code that I have read, Setfocus and Refresh are always followed by (). In my code I have not used the brackets and all works fine. Is it just a standard rule to use the brackes or am I going to run into problems later by writing sloppy code?

I think the convention is to use the () to distinguish a method from a property. In the case of SetFocus() and Refresh(), it's obvious, but for other methods, it may cause confusion.