How to get the height of a body element

Question

Here the total height of all <div>'s are 900 pixels, but the jQuery function returns the height of the body as 577 pixels. (If I remove the body CSS, it's working).

Is there a solution for this problem?

$j(function() {
    alert($j("body").height());
})

html, body {
    height:100%;
}

<div style="height:200px">header</div>
<div style="height:500px">content</div>
<div style="height:200px">footer</div>

Answer 1

Simply use

$(document).height() // - $('body').offset().top

and / or

$(window).height()

instead of $('body').height();