function setMenusFixation()
{
    if (!document.getElementById('navigation'))
        return;

    var width = 0;

    if (typeof(window.innerWidth ) == 'number' )
    {
        // Non-IE
        width = window.innerWidth;
    }
    else if (document.documentElement && document.documentElement.clientWidth)
    {
        // IE 6+ in 'standards compliant mode'
        width = document.documentElement.clientWidth;
    }
    else if (document.body && document.body.clientWidth)
    {
        //IE 4 compatible
        width = document.body.clientWidth;
    }

    if (width < 996)
    {
        document.getElementById('navigation').style.position = 'static';
    }
    else
    {
        document.getElementById('navigation').style.position = 'fixed';
    }
}

window.onload = setMenusFixation;
window.onresize = setMenusFixation;