This part of the site uses both an event handler (for the buttons) and a conditional statement (to make sure that the index does not try to use images that do not exist). When the "previous day" button is pressed, an event listener activates a function that updates a counter, provided that the counter is not greater than 5, and then changes the src attribute of the image to the value within an array at the index of the counter's value. The same thing happens with the "next day" button, but this time it subtracts from the counter. The reset button sets the counter to zero. I was going to use CSS to make the buttons gray out when the counter has reached its max, but I'm, running short on time.