Ok, I m stumped. Basically, this script works fine in FF, but not in IE (6,7 or 8) - in which it returns an "Object doesn t support this property or method" error. Any ideas?:

function portfolioAjaxLoader(page){
$("div#portfolio_container").load("include/DCK_portfolio_gallery.inc.php?cat=" + page);
}

$(document).ready(function(){

  $( a.portfolio_subnav ).livequery( click ,function(){
    portfolioAjaxLoader(this.title);
    return false;
    });

//modify page DOM if Javascript is switched on
$( div#gallery_frame ).livequery(function(){
    //assign portfolioAjaxLoader to sub navigation links

    gallery_frame = $( div#gallery_frame );
    //set gallery_strip width to the number of entries multiplied by width of gallery entry element
    gallery_strip = $( div#gallery_strip );
    gallery_entries = $( div#gallery_strip a );
    elementWidth = 235;
    gallery_strip_width = elementWidth*gallery_entries.length+ px ;
    gallery_strip.css({ width :gallery_strip_width});

    //add portfolio navigation buttons
    if(gallery_entries.length>4){
        $( div#portfolio_nav ).before( <p id="portfolio_nav_prev"></p><p id="portfolio_nav_next"></p> );
        }

    //assign event triggers to inserted portfolio nav elements
    prev = $("p#portfolio_nav_prev");
    next = $("p#portfolio_nav_next");

    scrollPrevMax = (((gallery_entries.length - 4) * elementWidth)+20);//tolerance
    scrollMax = ((gallery_entries.length - 5) * elementWidth);
    scrollMin = ((gallery_entries.length - 6) * elementWidth);
    });


    function nextAnim(){
        //remove handler
        next.unbind();

        var currentScrollPos = gallery_frame.scrollLeft();
        var targetPos = currentScrollPos + elementWidth;

        if(currentScrollPos > scrollMin){
           next.fadeOut("fast");
           }

        if(currentScrollPos >= 0){
           prev.fadeIn("fast");
           }


        gallery_frame.animate({scrollLeft:targetPos}, 300,  easeInOutQuart ,function(){next.bind( click ,nextAnim)});
        return false;
        }


    function prevAnim(){
        //remove handler
        prev.unbind();

        var currentScrollPos = gallery_frame.scrollLeft();
        var targetPos = currentScrollPos - elementWidth;

        if(currentScrollPos < scrollPrevMax){
            next.fadeIn("fast");
            }

        if((currentScrollPos == 0)||(currentScrollPos < elementWidth*2)){
            prev.fadeOut("fast");
            }

        gallery_frame.animate({scrollLeft:targetPos}, 300,  easeInOutQuart ,function(){prev.bind( click ,prevAnim)});
        //prev.bind( click ,prevAnim);
        return false;
        }

    next.click(nextAnim);
    prev.click(prevAnim);

});

I ve purposefully left some elements in the global scope (by omitting var in their declaration).

Just for the record, it reports the error here:

gallery_frame = $( div#gallery_frame );

Character 9, line 16.