<!--
function update() {

    margin = 150;
    offset = 30;

    if (document.layers) {

        if(window.pageYOffset < margin)
           position = margin;
        else
           position = document.body.scrollTop + offset;

        document.layers['sidebar'].pageY = position;
    }
    else if (document.all) {

        if(document.body.scrollTop < margin)
           position = margin;
        else
           position = document.body.scrollTop + offset;

        document.all['sidebar'].style.top = position;
    }
    else {

        if(document.body.scrollTop < margin)
           position = margin;
        else
           position = document.body.scrollTop + offset;

        document.getElementById("sidebar").style.top = position;
    }

    setTimeout('update()',300); //msec
}
//-->