FireFox dhtmlxtree javascript error

I have implemented the dhtmlxtree in When I open the page in IE, it works fine. When I open the page in FireFox, I get a javascript error that says: “this.parentObject has no properties” Line 63 in dhtmlxtree.js. My code follows:

Any idea what is going on?

In FF you must preserve case of ID attribute and value used in tree constructor
Currently you have

                <div id="treeBox"

which is not equal in case of FF

Thank you, that worked perfectly.