Q:

How to repeat a function call in jQuery

I have this code:
<script type="text/javascript" src="http://code.jquery.com/jquery-1.4.3.min.js"></script>
<script type="text/javascript">
    $(document).ready(function() { 
        function loop(){
            $('#picOne').fadeIn(0).fadeOut(8000);
            $('#picTwo').delay(2000).fadeIn(6000).fadeOut(5000);
            $('#picTree').delay(10000).fadeIn(2000).fadeOut(16000);
            $('#picFour').delay(12000).fadeIn(16000).fadeOut(5000);
        }
        loop();
    });
</script>

But when the last pic fades out, the code doesn't repeat. What is the problem?

A:

Assuming you want to duration of the animation being the same for each element:
var $elements = $('#picOne, #picTwo, #picTree, #picFour');

function anim_loop(index) {
    // Get the element with that index and do the animation
    $elements.eq(index).fadeIn(1000).delay(3000).fadeOut(1000, function() { 
        // Kind of recursive call, increasing the index and keeping in the
        // the range of valid indexes
        anim_loop((index + 1) % $elements.length);
    });
}

anim_loop(0); // start with the first element

I don't know exactly how the animation should be, but I hope it makes the concept clear.
Update: To simultaneously fade out and in an image after a certain time period, use setTimeout and call fadeOut and anim_loop in the callback:
$elements.eq(index).fadeIn(1000, function() {
    var $self = $(this);
    setTimeout(function() {
        $self.fadeOut(1000);
        anim_loop((index + 1) % $elements.length);
    }, 3000);
});

DEMO

