// jQuery.preloadImages = function() {
// 	for(var i = 0; i<arguments.length; i++) {
// 		jQuery("<img>").attr("src", arguments[i]);
// 	}
// }

var curSlide = 0;
	
function scrollBy (offset) {
	var element = $("#content-main");
	var contentHeight = $(element).height();
	var slideHeight = 368;
	var slideLimit = (Math.ceil(contentHeight / slideHeight) * -1) + 1;
	var curResult = curSlide + offset;
	
	if (curResult <= 0 && curResult >= slideLimit) {
		curSlide = curResult;
		var vShiftTo = slideHeight * curResult;
		element.animate ({
			top: vShiftTo
		}, 700);
		$("#scrollUp").fadeIn("fast");
		$("#scrollDown").fadeIn("fast");
		if (curResult == 0) {
			$("#scrollUp").fadeOut("fast");
		}
		if (curResult == slideLimit) {
			$("#scrollDown").fadeOut("fast");
		}
	}
}