Código para plegado/desplegado

/* Prerequisitos:
  var NavigationBarHide = 'Plegar';
  var NavigationBarShow = 'Desplegar';

  var NavigationBarShowDefault = 0;
*/


function toggleNavigationBar(indexNavigationBar)
{
    var NavToggle = document.getElementById("NavToggle" + indexNavigationBar);
    var NavFrame = document.getElementById("NavFrame" + indexNavigationBar);

    if (!NavFrame || !NavToggle) {
        return false;
    }

    // if shown now
    if (NavToggle.firstChild.data == NavigationBarHide) {
        for (
                var NavChild = NavFrame.firstChild;
                NavChild != null;
                NavChild = NavChild.nextSibling
            ) {
            if (NavChild.className == 'NavPic') {
                NavChild.style.display = 'none';
            }
            if (NavChild.className == 'NavContent') {
                NavChild.style.display = 'none';
            }
            if (NavChild.className == 'NavToggle') {
                NavChild.firstChild.data = NavigationBarShow;
            }
        }

    // if hidden now
    } else if (NavToggle.firstChild.data == NavigationBarShow) {
        for (
                var NavChild = NavFrame.firstChild;
                NavChild != null;
                NavChild = NavChild.nextSibling
            ) {
            if (NavChild.className == 'NavPic') {
                NavChild.style.display = 'block';
            }
            if (NavChild.className == 'NavContent') {
                NavChild.style.display = 'block';
            }
            if (NavChild.className == 'NavToggle') {
                NavChild.firstChild.data = NavigationBarHide;
            }
        }
    }
}

 // adds show/hide-button to navigation bars
 function createNavigationBarToggleButton()
 {
    var indexNavigationBar = 0;
    // iterate over all 
-elements
    for(
            var i=0; 
            NavFrame = document.getElementsByTagName("div")[i]; 
            i++
        ) {
        // if found a navigation bar
        if (NavFrame.className == "NavFrame") {

            indexNavigationBar++;
            var NavToggle = document.createElement("a");
            NavToggle.className = 'NavToggle';
            NavToggle.setAttribute('id', 'NavToggle' + indexNavigationBar);
            NavToggle.setAttribute('href', 'javascript:toggleNavigationBar(' + indexNavigationBar + ');');

            var NavToggleText = document.createTextNode((document.getElementById('DontHideNavigationBars')) ? NavigationBarHide : NavigationBarShow );
            NavToggle.appendChild(NavToggleText);

            // add NavToggle-Button as first div-element 
            // in 

            NavFrame.insertBefore(
                NavToggle,
                NavFrame.firstChild
            );
            NavFrame.setAttribute('id', 'NavFrame' + indexNavigationBar);
        }
    }

    //Por defecto están todas desplegadas: plegar a menos que la página sea una excepción, incluyendo un elemento con Id 'DontHideNavigationBars'.
    if (document.getElementById('DontHideNavigationBars')) return;

        for(
                var i=1; 
                i<=indexNavigationBar; 
                i++
        ) {
            toggleNavigationBar(i);
            toggleNavigationBar(i);
        }

    // if less o equal Navigation Bars found than Default: show all
    if (NavigationBarShowDefault >= indexNavigationBar) {
        for(
                var i=1; 
                i<=indexNavigationBar; 
                i++
        ) {
            toggleNavigationBar(i);
        }
    }
    
 }

 if (window.addEventListener) window.addEventListener("load",createNavigationBarToggleButton,false);
 else if (window.attachEvent) window.attachEvent("onload",createNavigationBarToggleButton);

//