/** Initiate when DOM is ready */
$(document).ready(function(){
    $(".star-1").nightSky();
    $(".star-2").nightSky();
    $(".star-3").nightSky();
    $(".star-4").nightSky();
});

/**
* jQuery plugin
*/
jQuery.fn.nightSky = function(options)
{
    var animationStarted = false;
	var settings = {
		fadeInSpeed: 800,
		fadeOutSpeed: 600,
		maxInterval: 6000,
		minInterval: 4000,
		showTime: 600
	};

	settings = jQuery.extend(settings, options || {});
    
    var animate = function(obj)
    {
        if (animationStarted)
        {
    		if (obj.is(":visible"))
            {
                obj.fadeOut(settings.fadeOutSpeed);
            }
            else
            {
                obj.fadeIn(settings.fadeInSpeed);
                setTimeout(function(){ obj.fadeOut(settings.fadeOutSpeed); }, settings.showTime);
            }
        }
        
        var interval = 0;
        while (interval < settings.minInterval)
        {
            interval = Math.floor(Math.random() * settings.maxInterval);
        }
        
        setTimeout(function(){ animate(obj); }, interval);
        
        animationStarted = true;
	}
    
	return this.each(function() {
		var _this = jQuery(this);
		
		_this.fadeOut("fast");
		animate(_this);
	});
};