Open titlepage.fpi in languagebank\your language used\gamebank\mygame\
and you'll see a line like this :
:state=0:hudreset,hudx=50,hudy=65,hudimage=languagebank\english\gamecore\backdrops\basic\exitgame.tga,hudtype=5,hudmake=button
This is a button with an id set to it (hudtype).
Now later on you'll see
:state=2,hudselectionmade=5:quitgame,destroy
Which would mean when you click the button graphic with id 5 , the game will exit.The same way you can make your own pages
:state=0:hudreset,hudx=50,hudy=65,hudimage=path to button image,hudtype=6(or whatever you want),hudmake=button
Then add another line in the end of the script
:state=2,hudselectionmade=6(or other number):do something...