//credit: http://www.mattfarina.com/2007/02/01/preloading_images_with_jquery
$.preloadImages = function()
{
	for (var i = 0; i < arguments.length; i++)
	{
		jQuery("<img>").attr("src", arguments[i]);
	}
} 

function diffMatch(value, target, diff)
{
	if (!diff)
		diff = 40;

	if (value >= target - diff && value <= target + diff)
		return true;
	else
		return false;
}