In preparation for this one, some back-story is warranted. One useful tag in the HTML specification was not always supported by all major browsers, the IFRAME. The tag is now supported by all major browsers.
Use the SRC attribute to set the external or internal page to be displayed within this specified division of the page.
<form action="javascript:" method="get">
<input id="submit" type="button" value="i can has search?"/>
</form>
<noscript>JavaScript is disabled.</noscript>
<script type="text/javascript">
$('submit').addEvent('click', function() {
// use mootools to create an iframe element
new Element('iframe', {
'src' : 'http://google.com',
'frameborder': 1,
'width' : 800,
'height' : 400
}).replaces($('submit'));
});
</script>