lib/Ext/dom/Element.js
function() {
        this.isDestroyed = true;

        var cache = Ext.Element.cache,
            dom = this.dom;

        if (dom && dom.parentNode && dom.tagName != 'BODY') {
            dom.parentNode.removeChild(dom);
        }

        delete cache[this.id];
        delete this.dom;
    }
function() {
        this.isDestroyed = true;

        var cache = Ext.Element.cache,
            dom = this.dom;

        if (dom && dom.parentNode && dom.tagName != 'BODY') {
            dom.parentNode.removeChild(dom);
        }

        delete cache[this.id];
        delete this.dom;
    }
Removes this element's DOM reference. Note that event and cache removal is handled at {@link Ext#removeNode}