Untitled

<html><head>
<link rel="javascript" href="script.js">
</head><body>
<a href="javascript:display1()">Slide 1</a> | <a href="javascript:display2()">Slide 2</a>
<br><span id="display"></span>
<script src="script.js"></script>
</body></html>

function display1() {document.getElementById('display').innerHTML = '<iframe href="slide1.html"></iframe>';};
function display2() {document.getElementById('display').innerHTML = '<iframe href="slide2.html"></iframe>';};

<span id="display">
<iframe href="slide1.html></iframe>
</span>

<span id="display">
<iframe href="slide1.html>
#document
<html>
<head></head>
<body></body>
</html>
</iframe>
</span>

<span id="display">
<iframe href="slide1.html>
#document
<html>
<head></head>
<body><b>Slide 1</b></body>
</html>
</iframe>
</span>

.innerHTML = '<iframe src="slide1.html"></iframe>';};