window.addEventListener("load",initAll,false);
var xhr = false;
var xPos, yPos;
function initAll() {
var allLinks = document.getElementsByTagName("a");
for (var i=0; i< allLinks.length; i++) {
allLinks[i].addEventListener("mouseover",getPreview,false);
}
}
function getPreview(evt) {
if (evt) {
var url = evt.target;
}
else {
evt = window.event;
var url = evt.srcElement;
}
xPos = parseInt(evt.clientX);
yPos = parseInt(evt.clientY);
if (window.XMLHttpRequest) {
xhr = new XMLHttpRequest();
}
else {
if (window.ActiveXObject) {
try {
xhr = new ActiveXObject("Microsoft.XMLHTTP");
}
catch (e) {
}
}
}
if (xhr) {
xhr.addEventListener("readystatechange",showContents,false);
xhr.open("GET", url, true);
xhr.send(null);
}
else {
alert("Sorry, but I couldn't create an XMLHttpRequest");
}
}
function showContents() {
var prevWin = document.getElementById("previewWin");
if (xhr.readyState == 4) {
if (xhr.status == 200) {
prevWin.innerHTML = xhr.responseText;
}
else {
prevWin.innerHTML = "There was a problem with the request " + xhr.status;
}
prevWin.style.top = yPos+2 + "px";
prevWin.style.left = xPos+2 + "px";
prevWin.style.visibility = "visible";
prevWin.addEventListener("mouseout", function() {prevWin.style.visibility = "hidden";}, false);
}
}
<!DOCTYPE html>
<html>
<head>
<title>Previewing Links</title>
<link rel="stylesheet" href="script05.css">
<script src="script05.js"></script>
</head>
<body>
<h2>A Gentle Introduction to JavaScript</h2>
<ul>
<li><a href="jsintro/2000-08.html">August column</a></li>
<li><a href="jsintro/2000-09.html">September column</a></li>
<li><a href="jsintro/2000-10.html">October column</a></li>
<li><a href="jsintro/2000-11.html">November column</a></li>
</ul>
<div id="previewWin"> </div>
</body>
</html>
#previewWin {
background-color: #FF9;
width: 400px;
height: 100px;
font: .8em arial, helvetica, sans-serif;
padding: 5px;
position: absolute;
visibility: hidden;
top: 10px;
left: 10px;
border: 1px #CC0 solid;
clip: auto;
overflow: hidden;
}
#previewWin h1, #previewWin h2 {
font-size: 1.0em;
}
Here is the code but let's see what is happening first