function showChart(nChart)
{
	oChartDiv = document.getElementById("chart");
	oLinkLi = document.getElementById("link" + nChart);
	nShift = -( (nChart - 1) * 381);
	oChartDiv.style.backgroundPosition = "0 " + nShift + "px";
	
	oLinkLi.className = "on";

	for ( n = 1; n <= 4; n++ )
	{
		if ( n != nChart )
		{
			oLinkLiOff = document.getElementById("link" + n);
			oLinkLiOff.className = "off";
		}
	}
}