How to insert a document from Google Docs in a post to LJ?

Ran into this issue trying to embed html code offered by Google to share a document in a LiveJournal post.
This code is an iframe tag, but some tags, as it turned out, LJ is prohibited and sending the post just cut from him.
I learned about a wonderful tag you want to wrap the inserted element, replacing on . This solution works in Opera, chrome, fierfox, but not in ie-8.