1st you have to make a button using some sort of paint program
then youd have to load it and position it onscreen
then you have to find where on screen the button is, add
print mousex()
print mousey()
and then move your mouse around to find out the coordinates of the button.. then in your code see if the mouse is positioned within those coordinates.. and if it is, and you click, then the game loads or whatever..
something like this might work..
check every corner of the box to see where it is.. pretend it exists at.. (0,0) (0,2) (2,0) and (2,2) even tho then it would be a tiny tiny square ^.^
anywayz..
if mousex() > 0 and mousex() < 2 and mousey() > 0 and mousey() < 2 and mouseclick = 1 then print "blahdeblah"
i hope that makes since.. in this case if you clicked in the tiny box, the screen would print "blahdeblah" on it and u would know its working
but if your just starting a game, you probally shouldn't start with the User interface like that.. that should probally come last..
altho im relatively new to all this, i know you should work on your basic game 1st.. instead of models use cubes to represent them and figure out the movement and shooting system and all that stuff 1st.