if (document.images) {

    barbiehistoryon = new Image();
    barbiehistoryon.src = "/images/collector/sidenav/barbie_history_on.gif";
    barbietriviaon = new Image();
    barbietriviaon.src = "/images/collector/sidenav/barbie_trivia_on.gif";
    
    barbiehistoryoff = new Image();
    barbiehistoryoff.src = "/images/collector/sidenav/barbie_history_off.gif";
    barbietriviaoff = new Image();
    barbietriviaoff.src = "/images/collector/sidenav/barbie_trivia_off.gif";
}