Since the wiki doesn't give any examples of custom GUIs, I'll be nice and answer your question. I believe
showstats(1024); would go in the
onCreated() part of the script.
As many people have told you, the GraalBible is an excellent source of information. Before asking questions on the forums, you should search the GraalBible for information regarding your problem. The GScript information section is at this URL:
http://graal.net/index.php/Creation/Dev/GScript