function getSize() {
	slideWidth = document.getElementById("slideImg").offsetWidth;
	switch (slideWidth) {
		case 223:
		imgData = new Array(slideWidth, -1338, 'slideImg');
		return imgData;
		
		case 261:
		imgData = new Array(slideWidth, -1827, 'slideImg');
		return imgData;
		
		case 243:
		imgData = new Array(slideWidth, -972, 'slideImg');
		return imgData;
		
		case 201:
		imgData = new Array(slideWidth, -804, 'slideImg');
		return imgData;
		
		case 364:
		imgData = new Array(slideWidth, -1820, 'slideImg');
		return imgData;
	}
}

function moveImg(option) {
	var imgData = getSize();
	posX = parseInt(document.getElementById(imgData[2]).style.backgroundPosition);
	if (option == "next") {
		if (isNaN(posX)) {
			posX = 0;
			posX = posX - imgData[0];
		}
		else if (posX == imgData[1]) {
			posX = 0;
		}
		else {
			posX = posX - imgData[0];
		}
	}
	else if (option = "back") {
		if (isNaN(posX) || posX == 0) {
			posX = imgData[1];
		}
		else {
			posX = posX + imgData[0];
		}
	}
	document.getElementById(imgData[2]).style.backgroundPosition = posX + 'px 0px';
}