gistfile1.js

function f() {
    i=0;
    d=['n','s'];
    // Call the first argument at an interval of 150ms
    setInterval(function() {
        $('.eye').each(function() { // Find all elements with a class of eye
            // for each element change the src attribute to either the North or South image
            // img_base is defined in the lateral-eye.js file from the webpage
            $(this).attr('src',img_base+$(this).attr('rel')+'_'+d[i]+'.jpg')
        });
        // Toggles the image between n and s
        // i = 0 to start
        // (0 + 1) mod 2 == 1
        // (1 + 1) mod 2 == 0
        i = (i+1) % d.length;
    },150);
}
f()