/**
 * update footer position
 */
function setFooter() {
    var windowTop       = $(window).scrollTop();
    var windowHeight    = $(window).height();
    var leftPosition    = $('#block_left').offset();
    var leftHeight      = $('#block_left').height();
    var $footer         = $('#footer_left');
    var footerHeight    = $footer.height();
    
    if (leftPosition.top + leftHeight + footerHeight < windowHeight + windowTop) {
        if ($.browser.msie && (jQuery.browser.version < 7)) {
            $footer .css('position', 'absolute')
                    .css('top', windowHeight + windowTop - footerHeight);
        } else {
            $footer .css('position', 'fixed')
                    .css('bottom', '0');
        }
    } else {
        $footer .css('position', 'static')
                .css('top', '')
                .css('bottom', '');
    }
}

$(document).ready(function() {
   $(window).load(setFooter)
            .resize(setFooter)
            .scroll(setFooter);
});