// JavaScript Document
function chgClass(layerID, selectClass, unSelectClass, linkID, linkContent)
{
	var i=1;
	while(document.getElementById(linkID+i))
	{
		document.getElementById(linkID+i).className=unSelectClass;
		document.getElementById(linkContent+i).style.display='none';
		i+=1;
	}
	document.getElementById(linkID+layerID).className=selectClass;
	document.getElementById(linkContent+layerID).style.display='block';
}