I have an iframe and I want to clear it, so I set its src to about:blank
Then I wondered, does this work in all browsers?
One thing to be aware of is that if you are running a website in https, you need to be careful about blanking out an iframe. about:blank is a non-secure page and so the browser will throw an error to the user that there are non-secure sections of the page if you have an iframe sourced to about:blank.
(Not exactly an answer to your question, but I thought it was worth mentioning)