/* requires jQuery */

var SpriteRunning = false;

function Random(min, max) {
	return Math.round(Math.random()*(max-min) + min);
}

function RndX(width) {
  return Random(0, window.innerWidth - width);
}

function RndY(height) {
  return Random(0, window.innerHeight - height);
}

function startSprite(id) {
	obj = $(id);
	obj.css({left:RndX(obj.width())+'px', top:RndY(obj.height())+'px'});
	obj.fadeIn(5000);
	obj.animate({left:RndX(obj.width()), top:RndY(obj.height())}, Random(1000, 10000), 'swing');
	obj.fadeOut(2000, function(){
    if (SpriteRunning) {
      window.setTimeout(function(){ startSprite(id); }, Random(4000, 10000));
    }
  });
}

function initSprite(id) {
	obj = $(id);
	obj.css({visibility:'visible', display:'none', position:'absolute'});
	window.setTimeout(function(){ startSprite(id); }, Random(3000, 20000));
	SpriteRunning = true;
}

function stopSprite(id) {
	SpriteRunning = false;
}