function nbInitVars() {
    nbPosition = new Array (0,0,0,0);
    nbSpeed = new Array (0,0,0,0);
    nbAccel = new Array (0,0,0,0);
    nbHidden = new Array (true,true,true,true);
    nbOpen = new Array (false,false,false,false);
    nbTimeout = new Array (0,0,0,0)
}
function nbTrace() {
    for (i=0; i<4; i++) {
        if ((!nbHidden[i]) && (!nbOpen[i])) {
            nbSpeed[i] += nbAccel[i];
            nbPosition[i] += nbSpeed[i];
            if (nbPosition[i] > 49) {
                nbOpen[i] = true;
                nbTimeout[i] = 125;
                nbSpeed[i] = 0;
                nbAccel[i] = 0;
                nbPosition[i] = 50
            };
            if (nbPosition[i] < 1) {
                nbHidden[i] = true;
                nbSpeed[i] = 0;
                nbAccel[i] = 0;
                nbPosition[i] = 0;
                document.getElementById("nb_item_" + (i + 1)).style.display = "none"
            };
            document.getElementById("nb_item_" + (i + 1)).style.top = nbPosition[i] - 50
        };
        if (nbOpen[i]) {
            nbTimeout[i]--;
            if (nbTimeout[i] == 0) {
                nbOpen[i] = false;
                nbAccel[i] = -2
            }
        }
    };
    setTimeout("nbTrace()",10)
}
function nbInit() {
    document.getElementById('nbFlash').style.visibility = 'visible';
    nbInitVars();
    nbTrace();
}
function nbOpenItem(idNum) {
    for (i=0; i<4; i++) {
        if (!nbHidden[i]) {
            nbAccel[i] = -2;
            nbOpen[i] = false
        }
    };
    nbAccel[idNum-1] = 2;
    nbHidden[idNum-1] = false;
    document.getElementById("nb_item_" + idNum).style.display = "block"
}