function updateNav(pageID){
	if (document.getElementById && pageID){
		if (pageID.length==6){
			document.getElementById('li'+pageID).className="active";
			pageID=pageID.slice(0,-2);
		}
		if (pageID.length==4){
			//alert(pageID);
			document.getElementById('li'+pageID).className="active";
			if (document.getElementById('ul'+pageID)){
				document.getElementById('ul'+pageID).style.display="block";
			}
			pageID=pageID.slice(0,-2);
		}
		if (document.getElementById('ul'+pageID)){
			document.getElementById('ul'+pageID).style.display="block";
		}
		document.getElementById('li'+pageID).className="active";
	}
}

// JavaScript to interpolate random images into a page.
var ic = 12;     // Number of alternative images
var illus = new Array(ic);  // Array to hold filenames
var alttext = new Array(ic); //Array to hold alt text
        
illus[0] = "/images/bkheader_home01.jpg";
illus[1] = "/images/bkheader_home02.jpg";
illus[2] = "/images/bkheader_home03.jpg";
illus[3] = "/images/bkheader_home04.jpg";
illus[4] = "/images/bkheader_home05.jpg";
illus[5] = "/images/bkheader_home06.jpg";
illus[6] = "/images/bkheader_home07.jpg";
illus[7] = "/images/bkheader_home08.jpg";
illus[8] = "/images/bkheader_home09.jpg";
illus[9] = "/images/bkheader_home10.jpg";
illus[10] = "/images/bkheader_home12.jpg";
illus[11] = "/images/bkheader_home13.jpg";

alttext[0] = "NYC skyline";
alttext[1] = "NYC cabs";
alttext[2] = "a boat moving through water";
alttext[3] = "the windows of a skyscraper";
alttext[4] = "a traditional building";
alttext[5] = "looking up to the sky";
alttext[6] = "the dome of a building";
alttext[7] = "a busy intersection";
alttext[8] = "the supreme court";
alttext[9] = "Washington DC Metro Station";
alttext[10] = "New York Stock Exchange";
alttext[11] = "Lincoln Memorial";



function pickRandom(range) {
if (Math.random)
return Math.round(Math.random() * (range-1));
else {
var now = new Date();
return (now.getTime() / 1000) % range;
}
}
// Write out an IMG tag, using a randomly-chosen image name.
var choice = pickRandom(ic);