function dsp(loc) {
    if (document.getElementById) {
        var foc = loc.firstChild;
        foc = loc.firstChild.innerHTML ? loc.firstChild : loc.firstChild.nextSibling;
        var th = document.getElementById(loc);
        if (th != null) {
            foc.innerHTML = foc.innerHTML == "+" ? "-" : "+";
        }
        foc = loc.parentNode.nextSibling.style ? loc.parentNode.nextSibling : loc.parentNode.nextSibling.nextSibling;
        foc.style.display = foc.style.display == "block" ? "none" : "block";
    }
}