button_next.onPress = function()
{
 n++
 if (n>=xmax) n=xmax-1
//this line checks if the n
(variable added up previously else load_pictures(n)
//will be bigger than the bounds in the x coordinates
}
//otherwise it is going to call the function to load the
//pictures Doing the same for the previous button…
button_prev.onPress = function()
{
n--
//takes the counter down by one
if (n<0) n=0
//checks if the you are in the first picture or not
else load_pictures(n)
//otherwise it loads the picture.
}