function getWindowHeight()
{
    var windowHeight=0;
    if (typeof(window.innerHeight) == 'number')
    {
        windowHeight = window.innerHeight;
    }
    else
    {
        if (document.documentElement && document.documentElement.clientHeight)
        {
            windowHeight = document.documentElement.clientHeight;
        }
        else
        {
            if (document.body && document.body.clientHeight)
            {
                windowHeight = document.body.clientHeight;
            }
        }
    }
    return windowHeight;
}

function setFooter()
{
    if((document.all) && (document.getElementById))
    {
        var windowHeight = getWindowHeight();
        if (windowHeight>0)
        {
            var contentHeight = document.getElementById('content').offsetHeight;
            var footerElement = document.getElementById('footer');
            var footerHeight = footerElement.offsetHeight;
            if (windowHeight - (contentHeight+footerHeight) < 0)
            {
                document.all.footer.style.marginTop = '3.5em';
            }
        }
    }
}