function GetXmlHttpObject()
{
	var xmlHttp = null;
	
	try
	{
		// Firefox, Opera 8.0+, Safari
		xmlHttp=new XMLHttpRequest();
	}
	catch (e)
	{
		// Internet Explorer
		try
		{
			xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
		}
		catch (e)
		{
			xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
		}
	}
	
	return xmlHttp;
}

function setContent(htmlText)
{
	document.getElementById("center_section").innerHTML = htmlText;
	initLightbox();
}

function loadPage(which)
{
	var xmlHttp = GetXmlHttpObject();
	
	if (xmlHttp==null)
	{
		alert("You need to upgrade your browser to use this website.");
		return;
	}
	
	var url = which + ".shtml?" + randomString();

	xmlHttp.onreadystatechange = function() { if( xmlHttp.readyState == 4 ) { setContent(xmlHttp.responseText); } };
	xmlHttp.open("GET",url,true);
	xmlHttp.send(null);	
}

function randomString()
{
	var chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz";
	var string_length = 30;
	var randomstring = '';
	for (var i=0; i<string_length; i++) {
		var rnum = Math.floor(Math.random() * chars.length);
		randomstring += chars.substring(rnum,rnum+1);
	}
	return randomstring;
}