[thelist] onclick event

[Fred D Yocum]

Apologies for the length of this post. I have been going around in circles 
for about a day now. 

I have a nested set of ordered lists which has six levels -- it is a sort 
of index of about six hundred document/document fragments. 
 
I want my DOM script to  check each ordered list to see whether it is 
contained in a list item (li). If it is nested in a list item, then set 
the display for the ordered list to hidden and add an element, to the 
parent list item. This element when clicked will reset the display of the 
nested list to "block", making it visible. This way people can click their 
way deeper into the index, making each level visible when they need it.

Every thing works except the onclick which appears to do nothing... I 
tried a direct statement
 downObject.onclick = thisOL.style.display="block";//hide the existing 
list

I've tried it in a function literal
downObject.onclick = function () { //add an onclick event
                                thisOL.style.display="block";//hide the 
existing list
                                }
Nothing works :-(

Here is the full script
________________

function PrepWindow(){
 
var theContent = document.getElementById('MainContent'); //Find the main 
content
var listOL = theContent.getElementsByTagName('ol');  //Find all of the 
nested ordered list

        for (var a=0; a < listOL.length; a++){  //Loop through the list 
items 
                var thisOL = listOL[a];
                 if(thisOL.parentNode.nodeName =="LI") {  //Check for 
containing lists
                        olContainer = thisOL.parentNode; //identify the 
containing li item
                        thisOL.style.display="none"; //hide the existing 
list
 
                        var downObject = 
document.createElement('span');//Create a span which is the close area
                        downObject.setAttribute('class','downLevel'); 
//give it a class
 
                        var downImg = document.createElement('img'); 
//Create the down img
                        downImg.setAttribute('src', 
'webres/downlevel.gif');
                        downImg.setAttribute('alt','Down a level');
                        downImg.setAttribute('width','19');
                        downImg.setAttribute('height','14');
 
                        downObject.appendChild(downImg); //Put it down img 
into the span
 
                        downObject.onclick = function () { //add an 
onclick event
                                thisOL.style.display="block";//hide the 
existing list
                                }
 
                        olContainer.appendChild(downObject); //Put the 
span into the document next to the ordered list 
                        }
                }
        }


window.onload = PrepWindow; //Call the javascript for this page

_________________________________________
TIA 
Frederick D Yocum