var loaded = false;
ie = (document.all)? true:false;
ns = (document.layers)? true:false;
ns6 = (document.getElementById)? true:false;//ie5 compatible

function newImage(arg) {
        if (document.images) {
                rslt = new Image();
                rslt.src = arg;
                return rslt;
        }
}

function changeImages() {
        if (document.images && (preloadFlag == true)) {
                for (var i=0; i<changeImages.arguments.length; i+=2) {
                        document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
                }
        }
}

var preloadFlag = false;
function preloadImages() {
        if (document.images) {
                m_01_over = newImage("images/m_lens_on.gif");
                m_02_over = newImage("images/m_lens_on.gif");
                m_03_over = newImage("images/m_spec_on.gif");
                m_04_over = newImage("images/m_report_on.gif");
                m_05_over = newImage("images/m_catalog_on.gif");
                m_06_over = newImage("images/m_dl_on.gif");
                preloadFlag = true;
        }
}