Enable/Disable WYSIWYG Editor?

I have a form textarea that I can disable/enable using javascript:

document.getElementById('mytextarea').disabled=true

I have now replaced the textarea with a WYSIWYG editor called openwysiwyg http://www.openwebware.com/ but now I can't disable/enable using the javascript method. I've even tried disabling the whole row that the textarea appears in but the WYSIWYG editor still allows the user to type.

Any ideas? Thanks.

I think you can't disable OR enable but as an another option you can try to hide that span or row.