var req;
var bookID;
var url="xml/books.xml";

function bookInfo(book) {
    if (window.XMLHttpRequest) {
        req = new XMLHttpRequest();
        req.onreadystatechange = processReq;
        req.open("GET", url, true);
        req.send(null);
    } else if (window.ActiveXObject) {
        req = new ActiveXObject("Microsoft.XMLHTTP");
        if (req) {
            req.onreadystatechange = processReq;
            req.open("GET", url, true);
            req.send();
        }
    }
	bookID=book;
}


function processReq() {
    if (req.readyState == 4) {
        if (req.status == 200) {
			var xml = req.responseXML;
			var allBooks = xml.getElementsByTagName("book");
			var bookNum;
			for(var i=0; i<allBooks.length; i++){
				var book = allBooks[i];
				bookNum = book.attributes.getNamedItem("id").value;
				if(bookNum==bookID) {
					var title = book.getElementsByTagName("title")[0].firstChild.nodeValue;
					var length = book.getElementsByTagName("length")[0].firstChild.nodeValue;
					var price = book.getElementsByTagName("price")[0].firstChild.nodeValue;
					var img = book.getElementsByTagName("image")[0].firstChild.nodeValue;
					var desc = book.getElementsByTagName("description")[0].firstChild.nodeValue;
					updatePage(title, length, price, img, desc);
				}					
			}

       }
	  
    }
function updatePage(title, length, price, img, desc) {
	var imgDest = document.getElementById('selBookImage');
	var imgSrc = "img/"+img;
	imgDest.setAttribute("src", imgSrc);
	imgDest.setAttribute("alt", "selected book image");
	imgDest.style.border = '2px solid black';
	imgDest.style.width = '216px';
	
	
	var titleSpace = elem("selBookTitle");
	var titleH3 = document.createElement("h3");
	var titleTxt = document.createTextNode(title);
	titleH3.appendChild(titleTxt);
	titleSpace.replaceChild(titleH3, titleSpace.firstChild);
	
	var lengthSpace = elem("selBookLength");
	var lengthP = document.createElement("p");
	var lengthTxt = document.createTextNode(length);
	lengthP.appendChild(lengthTxt);
	lengthSpace.replaceChild(lengthP, lengthSpace.firstChild);
	
	var priceSpace = elem("selBookPrice");
	var priceP = document.createElement("p");
	var priceTxt = document.createTextNode(price);
	priceP.appendChild(priceTxt);
	priceSpace.replaceChild(priceP, priceSpace.firstChild);
	
	var descSpace = elem("selBookDesc");
	var descP = document.createElement("p");
	var descTxt = document.createTextNode(desc);
	descP.appendChild(descTxt);
	descSpace.replaceChild(descP, descSpace.firstChild);
	
	var head = elem("selTitle");
	var headH1 = document.createElement("h1");
	var headTxt = document.createTextNode("  ");
	headH1.appendChild(headTxt);
	head.replaceChild(headH1, head.firstChild);
	
	var table = elem("descTab");
	
	table.style.background = '#cb914d';
    table.style.border = '1px solid #025b2f';
}

}