function toggle(id) {
    if (document.getElementById) {
        obj = document.getElementById(id);
    }
    if (document.all) {
        obj = document.all[id];
    }
    if (document.layers) {
        obj = document.layers[id];
    }
    if (obj) {
        if (obj.style.display == "none") {
            obj.style.display = "";
        } else {
            obj.style.display = "none";
        }
    }
    return;
}

var iconClose = new Image();
iconClose.src = '../images/icons/plus.gif';
var iconOpen = new Image();
iconOpen.src = '../images/icons/minus.gif';

function toggleIcon(iconName) {
    if (document.images[iconName].src == window.iconOpen.src) {
        document.images[iconName].src = window.iconClose.src;
    } else if (document.images[iconName].src == window.iconClose.src) {
        document.images[iconName].src = window.iconOpen.src;
    }
    return;
}