var imageNumber = 1;

function refreshImage()
{
	//alert("refreshImage"+imageNumber);
	var imageNode = document.getElementById("main_image");
	imageNode.src = "tux" + imageNumber + ".jpg";
}

function display(newImageNumber)
{
	if(imageNumber != newImageNumber)
	{
		imageNumber = newImageNumber;
		refreshImage();
	}
}

function displayPrevious()
{
	if(imageNumber>1)
	{
		imageNumber = imageNumber - 1;
		refreshImage();
	}
}

function displayNext()
{
	if(imageNumber<9)
	{
		imageNumber = imageNumber + 1;
		refreshImage();
	}
}