How can I force my footer to stick to the bottom of any page in CSS?

Question

This is my code:

#footer {
   font-size: 10px;
   position:absolute;
   bottom:0;
   background:#ffffff;
}

I've no idea what is wrong with this - can anyone help?

EDIT: For some more clarity on what's wrong: The footer is displayed on the bottom as expected when the page loads. However, when the web page's height is > than the dimensions on the screen such that a scroll bar appears, the footer stays in that same location. That is to say, when the height of the page is <= 100%, the footer is at the bottom. However, when the page height is >100%, the footer is NOT at the bottom of that page, but at the bottom of the visible screen instead.

EDIT: Surprisingly, none of the solutions below worked. I ended up implementing a sidebar instead.

Answer 1

You're probably looking for this example:

<div class="wrapper">
    Your content here
    <div class="push"></div>
</div>
<div class="footer">
    Your footer here
</div>

CSS:

For a 142-pixel footer

html, body {
    height: 100%;
}
.wrapper {
    min-height: 100%;
    height: auto !important;
    height: 100%;
    margin: 0 auto -142px; /* the bottom margin is the negative value of the footer's height */
}
.footer, .push {
    height: 142px; /* .push must be the same height as .footer */
}

/*

Sticky Footer by Ryan Fait
http://ryanfait.com/

*/