var xmlHttp
var gSpanId = 'usgs201', gTierId, gPage = 1, gMax = 9

var dsi=13;
var keyJ="74",keyj="106";
var keyK="75",keyk="107";
var x='';
function handler(e) 
{
	if (document.all) {
		var evnt = window.event; 
		x=evnt.keyCode;
	}
	else 
		x=e.charCode;
  
	if (x==keyK || x==keyk) getTourPage(gSpanId,gPage+1)
	if (x==keyJ || x==keyj) getTourPage(gSpanId,gPage-1)
}

function getTourPage(spanId,page)
{
	gSpanId = spanId
	if (page < 1) page = 1
	if (page > gMax) page = gMax
	gPage = page
	xmlHttp=GetXmlHttpObject()
	if (xmlHttp==null)
	{
		alert ("Browser does not support HTTP Request")
		return
	} 
	var url="usgr_ajax_tour.php"
	url=url+"?anchor="+spanId+"&page="+page
	xmlHttp.onreadystatechange=stateChanged 
	xmlHttp.open("GET",url,true)
	xmlHttp.send(null)
} 

function stateChanged() 
{ 
if (xmlHttp.readyState==4 || xmlHttp.readyState=="complete")
{ 
	var idCode = gSpanId
	var elem = document.getElementById(idCode+"s")
	var newSpan = document.createElement('span')
	newSpan.id = elem.id
	newSpan.innerHTML = xmlHttp.responseText
	for (var i = 0; i < document.getElementById(idCode).childNodes.length; i++) {
		var n = document.getElementById(idCode).childNodes[i]
		n.parentNode.removeChild(n)
	}
	document.getElementById(idCode).appendChild(newSpan) 
} 
} 

function GetXmlHttpObject()
{ 
var objXMLHttp=null
if (window.XMLHttpRequest)
{
objXMLHttp=new XMLHttpRequest()
}
else if (window.ActiveXObject)
{
objXMLHttp=new ActiveXObject("Microsoft.XMLHTTP")
}
return objXMLHttp
}