var imagePreload = [];

if (typeof document.addEventListener != 'function')
{	
	imagePreload.concat(['img/button_aa.gif', 'img/button_c3.gif', 'img/button_d4.gif', 'img/button_e6.gif']);
}

window.onload = function()
{
	// preload some images
	var imagePreloadLength = imagePreload.length;
	if(imagePreloadLength > 0)
	{
		var preloadedImages = [];
		var i;
		
		for(i = 0; i < imagePreloadLength; i++)
		{
			preloadedImages.push(new Image());
			preloadedImages[i].src = imagePreload[i];
		}
	}
}