$(document).ready(function() {
    var images = ['images/icon1.jpg', 'images/icon2.jpg', 'images/icon3.jpg',
				'images/icon4.jpg', 'images/icon5.jpg', 'images/icon6.jpg'];
    
    $('#randomImage').click(function() {
        var currentImage = $('#randomImage img').attr('src');
        var currentImageId = 0;

        for (key in images) {
            if (images[key] == currentImage) {
                currentImageId = parseInt(key);
            }
        }
        
        var image = images[currentImageId + 1];
        
        if (!image) {
            image = images[0];
        }

        $('#randomImage img').attr('src', image);
        
        return false;
    });    
        
});