The code below creates a nifty flyout menu action on a nested list item sequence. The client has called and wants the change the default behavior in which the flyouts are triggered by mouseover, so that you have to click to trigger a flyout.

Ideally, I would just like to modify this code so that you click on a small icon (plus/minus) that sits to the right of the menu item if it has child menus. Can someone give me a bit of guidance on what bits I'd need to change to accomplish this?

/* a few sniffs to circumvent known browser bugs */
var sUserAgent = navigator.userAgent.toLowerCase();
var isIE=document.all?true:false;
var isNS4=document.layers?true:false;
var isOp=(sUserAgent.indexOf('opera')!=-1)?true:false;
var isMac=(sUserAgent.indexOf('mac')!=-1)?true:false;
var isMoz=(sUserAgent.indexOf('mozilla/5')!=-1&&sUserAgent.indexOf('opera')==-1&&sUserAgent.indexOf('msie')==-1)?true:false;
var isNS6=(sUserAgent.indexOf('netscape6')!=-1&&sUserAgent.indexOf('opera')==-1&&sUserAgent.indexOf('msie')==-1)?true:false;
var dom=document.getElementById?true:false;

/* sets time until menus disappear in milliseconds */
var iMenuTimeout=1500;

var aMenus=new Array;
var oMenuTimeout;
var iMainMenusLength=0;

/* the following boolean controls the z-index property if needed */
/* if is only necessary if you have multiple mainMenus in one file that are overlapping */
/* set bSetZIndeces to true (either here or in the HTML) and the main menus will have a z-index set in descending order so that preceding ones can overlap */
/* the integer iStartZIndexAt controls z-index of the first main menu */
var bSetZIndeces=true;
var iStartZIndexAt=1000;
var aMainMenus=new Array;

/* load up the submenus */
function loadMenus(){
    if(!dom)return;
    var aLists=document.getElementsByTagName('ul');
    for(var i=0;i<aLists.length;i++){
        if(aLists[i].className=='navMenu')aMenus[aMenus.length]=aLists[i];
    }
    var aAnchors=document.getElementsByTagName('a');
    var aItems = new Array;
    for(var i=0;i<aAnchors.length;i++){
//      if(aAnchors[i].className=='navItem')aItems[aItems.length] = aAnchors[i];
        aItems[aItems.length] = aAnchors[i];
    }
    var sMenuId=null;
    var oParentMenu=null;
    var aAllElements=document.body.getElementsByTagName("*");
    if(isIE)aAllElements=document.body.all;
    /* loop through navItem and navMenus and dynamically assign their IDs */
    /* each relies on it's parent's ID being set before it */
    for(var i=0;i<aAllElements.length;i++){
        if(aAllElements[i].className.indexOf('x8menus')!=-1){
            /* load up main menus collection */
            if(bSetZIndeces)aMainMenus[aMainMenus.length]=aAllElements[i];
        }
//      if(aAllElements[i].className=='navItem'){
        if(aAllElements[i].tagName=='A'){
            oParentMenu = aAllElements[i].parentNode.parentNode;
            if(!oParentMenu.childMenus) oParentMenu.childMenus = new Array;
            oParentMenu.childMenus[oParentMenu.childMenus.length]=aAllElements[i];
            if(aAllElements[i].id==''){
                if(oParentMenu.className=='x8menus'){
                    aAllElements[i].id='navItem_'+iMainMenusLength;
                    //alert(aAllElements[i].id);
                    iMainMenusLength++;
                }else{
                    aAllElements[i].id=oParentMenu.id.replace('Menu','Item')+'.'+oParentMenu.childMenus.length;
                }
            }
        } else if(aAllElements[i].className=='navMenu'){
            oParentItem = aAllElements[i].parentNode.firstChild;
            aAllElements[i].id = oParentItem.id.replace('Item','Menu');
        }
    }
    /* dynamically set z-indeces of main menus so they won't underlap */
    for(var i=aMainMenus.length-1;i>=0;i--){
        aMainMenus[i].style.zIndex=iStartZIndexAt-i;
    }
    /* set menu item properties */
    for(var i=0;i<aItems.length;i++){
        sMenuId=aItems[i].id;
        sMenuId='navMenu_'+sMenuId.substring(8,sMenuId.lastIndexOf('.'));
        /* assign event handlers */
        /* eval() used here to avoid syntax errors for function literals in Netscape 3 */
        eval('aItems[i].onmouseover=function(){modClass(true,this,"activeItem");window.clearTimeout(oMenuTimeout);showMenu("'+sMenuId+'");};');
        eval('aItems[i].onmouseout=function(){modClass(false,this,"activeItem");window.clearTimeout(oMenuTimeout);oMenuTimeout=window.setTimeout("hideMenu(\'all\')",iMenuTimeout);}');
        eval('aItems[i].onfocus=function(){this.onmouseover();}');
        eval('aItems[i].onblur=function(){this.onmouseout();}');
        //aItems[i].addEventListener("keydown",function(){keyNav(this,event);},false);
    }
    var sCatId=0;
    var oItem;
    for(var i=0;i<aMenus.length;i++){
        /* assign event handlers */
        /* eval() used here to avoid syntax errors for function literals in Netscape 3 */
        eval('aMenus[i].onmouseover=function(){window.clearTimeout(oMenuTimeout);}');
        eval('aMenus[i].onmouseout=function(){window.clearTimeout(oMenuTimeout);oMenuTimeout=window.setTimeout("hideMenu(\'all\')",iMenuTimeout);}');
        sCatId=aMenus[i].id;
        sCatId=sCatId.substring(8,sCatId.length);
        oItem=document.getElementById('navItem_'+sCatId);
        if(oItem){
            if(!isOp && !(isMac && isIE) && oItem.parentNode)modClass(true,oItem.parentNode,"hasSubMenu");
            else modClass(true,oItem,"hasSubMenu");
            /* assign event handlers */
            eval('oItem.onmouseover=function(){window.clearTimeout(oMenuTimeout);showMenu("navMenu_'+sCatId+'");}');
            eval('oItem.onmouseout=function(){window.clearTimeout(oMenuTimeout);oMenuTimeout=window.clearTimeout(oMenuTimeout);oMenuTimeout=window.setTimeout(\'hideMenu("navMenu_'+sCatId+'")\',iMenuTimeout);}');
            eval('oItem.onfocus=function(){window.clearTimeout(oMenuTimeout);showMenu("navMenu_'+sCatId+'");}');
            eval('oItem.onblur=function(){window.clearTimeout(oMenuTimeout);oMenuTimeout=window.clearTimeout(oMenuTimeout);oMenuTimeout=window.setTimeout(\'hideMenu("navMenu_'+sCatId+'")\',iMenuTimeout);}');
            //oItem.addEventListener("keydown",function(){keyNav(this,event);},false);
        }
    }
}

/* this will append the loadMenus function to any previously assigned window.onload event */
/* if you reassign this onload event, you'll need to include this or execute it after all the menus are loaded */
function newOnload(){
    if(typeof previousOnload=='function')previousOnload();
    loadMenus();
}
var previousOnload;
if(window.onload!=null)previousOnload=window.onload;
window.onload=newOnload;

/* show menu and hide all others except ancestors of the current menu */
function showMenu(sWhich){
    var oWhich=document.getElementById(sWhich);
    if(!oWhich){
        hideMenu('all');
        return;
    }
    var aRootMenus=new Array;
    aRootMenus[0]=sWhich
    var sCurrentRoot=sWhich;
    var bHasParentMenu=false;
    if(sCurrentRoot.indexOf('.')!=-1){
        bHasParentMenu=true;
    }
    /* make array of this menu and ancestors so we know which to leave exposed */
    /* ex. from ID string "navMenu_12.3.7.4", extracts menu levels ["12.3.7.4", "12.3.7", "12.3", "12"] */
    while(bHasParentMenu){
        if(sCurrentRoot.indexOf('.')==-1)bHasParentMenu=false;
        aRootMenus[aRootMenus.length]=sCurrentRoot;
        sCurrentRoot=sCurrentRoot.substring(0,sCurrentRoot.lastIndexOf('.'));
    }
    for(var i=0;i<aMenus.length;i++){
        var bIsRoot=false;
        for(var j=0;j<aRootMenus.length;j++){
            var oThisItem=document.getElementById(aMenus[i].id.replace('navMenu_','navItem_'));
            if(aMenus[i].id==aRootMenus[j])bIsRoot=true;
        }
        if(bIsRoot && oThisItem)modClass(true,oThisItem,'hasSubMenuActive');
        else modClass(false,oThisItem,'hasSubMenuActive');
        if(!bIsRoot && aMenus[i].id!=sWhich)modClass(false,aMenus[i],'showMenu');
    }
    modClass(true,oWhich,'showMenu');
    var oItem=document.getElementById(sWhich.replace('navMenu_','navItem_'));
    if(oItem)modClass(true,oItem,'hasSubMenuActive');
}

function hideMenu(sWhich){
    if(sWhich=='all'){
        /* loop backwards b/c WinIE6 has a bug with hiding display of an element when it's parent is already hidden */
        for(var i=aMenus.length-1;i>=0;i--){
            var oThisItem=document.getElementById(aMenus[i].id.replace('navMenu_','navItem_'));
            if(oThisItem)modClass(false,oThisItem,'hasSubMenuActive');
            modClass(false,aMenus[i],'showMenu');
        }
    }else{
        var oWhich=document.getElementById(sWhich);
        if(oWhich)modClass(false,oWhich,'showMenu');
        var oThisItem=document.getElementById(sWhich.replace('navMenu_','navItem_'));
        if(oThisItem)modClass(false,oThisItem,'hasSubMenuActive');
    }
}

/* add or remove element className */
function modClass(bAdd,oElement,sClassName){
    if(bAdd){/* add class */
        if(oElement.className.indexOf(sClassName)==-1)oElement.className+=' '+sClassName;
    }else{/* remove class */
        if(oElement.className.indexOf(sClassName)!=-1){
            if(oElement.className.indexOf(' '+sClassName)!=-1)oElement.className=oElement.className.replace(' '+sClassName,'');
            else oElement.className=oElement.className.replace(sClassName,'');
        }
    }
    return oElement.className; /* return new className */
}

//document.body.addEventListener("keydown",function(){keyNav(event);},true); 

function setBubble(oEvent){
    oEvent.bubbles = true;  
}

function keyNav(oElement,oEvent){
    alert(oEvent.keyCode);
    window.status=oEvent.keyCode;
    return false;
}