If there was ever a time to hate IE, this is it. This code begins with a box with content. When the button is clicked, the box is supposed to drop down and fade-in.
Because you are missing the <head>
tag and doctype declaration, your page is being rendered in Quirks Mode. Change this
<html>
to this
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
<head>
I assume what you mean is that in IE, the item's height won't change. The element's height doesn't seem to get set to 0 properly. It works in my IE8 when I change
$('#test').height(0);
to
$('#test').height(1);
I don't know why this is. The documentation on height() does not mention any IE specific quirks.