$(document).ready(function(){
    var images = $('.promo a.image');
    images.mouseover(function(event) {
        $(this).find("img").each(function(i) {
            if (!this.src.match(/-hi\.[^.]*$/)) {
                var m = /\.[^.]*$/.exec(this.src);
                var base = this.src.substr(0, m.index);
                var ext = m[0];
                this.src = base + "-hi" + ext;
            }
        });
    });
    images.mouseout(function(event) {
        $(this).find("img").each(function(i) {
            if (this.src.match(/-hi\.[^.]*$/)) {
                var m = /\.[^.]*$/.exec(this.src);
                var ext = m[0];
                var base = this.src.substr(0, m.index - 3);
                this.src = base + ext;
            }
        });
    });
});