Problems with scrolling bars

[Abisso]

Sorry for my poor english (and this concludes the unuseful part of the message).

I've got a problem, in the Load and Save GUIs (created by myself) with the arrows (up and down) to scroll the saved games.
In the listbox, 3 saved games are visible, and when I click the down arrow (drawn on the gui) the game shows me the 3 next saved games. But when i arrive to the end of the list, clicking again, crashes the game.
I don't know how to forbid to a player to scroll down when the list of saved games reaches the end, or, better, to simply make the game do nothing, when this happens.

Please help me.

[Scummbuddy]

we'll need to see your code, because im assuming that its an error with your if statement or whatever function youre using, and you are going beyond your defined bounds.