<!-- // navroll.js navigation rollover script //
 if (document.images) {    
    home_Ov = new Image();
    home_Ov.src = "images/nav/home_ov.gif";
    welc_Ov = new Image();
    welc_Ov.src = "images/nav/welc_ov.gif";
    link_Ov = new Image();
    link_Ov.src = "images/nav/link_ov.gif";
    news_Ov = new Image();
    news_Ov.src = "images/nav/news_ov.gif";
    cont_Ov = new Image();
    cont_Ov.src = "images/nav/cont_ov.gif";
    gobackOv = new Image();
    gobackOv.src = "images/nav/back_Ov.gif";
    plot_Ov = new Image();
    plot_Ov.src = "images/nav/plot_ov.gif";

    home_Of = new Image();
    home_Of.src = "images/nav/home_of.gif";
    welc_Of = new Image();
    welc_Of.src = "images/nav/welc_of.gif";
    link_Of = new Image();
    link_Of.src = "images/nav/link_of.gif";
    news_Of = new Image();
    news_Of.src = "images/nav/news_of.gif";
    cont_Of = new Image();
    cont_Of.src = "images/nav/cont_of.gif";
    gobackOn = new Image();
    gobackOn.src = "images/nav/back_of.gif";
    plot_Of = new Image();
    plot_Of.src = "images/nav/plot_of.gif";
    
}

//rollover function on
function imgOv (imgName) {
        if (document.images) {
          document[imgName].src = eval(imgName + "_Ov.src");
        }
}

//rollover function off
function imgOf (imgName) {
        if (document.images) {
          document[imgName].src = eval(imgName + "_Of.src");
        }
}
//-->