Reposition drop down menu if near edge of window

I'm using the following code to reposition my drop down menus if they fall outside of the browser window area. However it does not work in Internet Explorer 7 and 8.

jQuery(document).ready(function(){
    jQuery("#nav>ul>li").each(function() {
        pos = jQuery(this).offset();
        if(pos.left + 100 > jQuery(window).width()+window.pageXOffset-jQuery(this).width()) {
        jQuery(this).addClass("nav-shift");}
    });
});

The window.pageXOffset property is not supported in IE (7 and 8, at least). Try $(window).offset().left instead:

jQuery(document).ready(function(){
    jQuery("#nav>ul>li").each(function() {
        pos = jQuery(this).offset();
        if(pos.left + 100 > jQuery(window).width()+jQuery(window).offset().left-jQuery(this).width()) {
        jQuery(this).addClass("nav-shift");}
    });
});

More readable, IMO:

jQuery(document).ready(function() {
    jQuery("#nav > ul > li").each(function() {
        var $this = jQuery(this),
            $win = jQuery(window);

        if ($this.offset().left + 100 > $win.width() + $win.offset().left - $this.width()) {
            $this.addClass("nav-shift");
        }
    });
});