External page won't show in iFrame

I have a form from a domain of mine that I would like to display on a different domain.  I made a new page, then a new html block and put this code in it.

<iframe width="600"  height="400" src="http://mysite.com/poststuff.php">
</iframe>

Nothing happens - that part of the page is blank.  Also, I noticed when I go back to the html block, and click to edit the html code- it is blank - there doesn't appear to be code in there, so I re-enter it - is that normal?   Why doesn't this iframe work?

dolphin kills iframe code.  have to insert it direct in the database

I have the same issue, open this link to see how to fix it.

http://www.boonex.com/forums/?action=goto&my_threads=1#topic/iframe-not-work-in-new-page.htm

Nothing is ever easy here, but at least some things have a solution.   Thanks for the info, and especially that reference link.

same problem here.. im using 7.0.7

 did you by chance take the adivce and review this post:

http://www.boonex.com/forums/?action=goto&my_threads=1#topic/iframe-not-work-in-new-page.htm

 iframes are not going to work, and shouldnt work from just simply inserting iframe source. this is a security measure. 

so the best method if you are insistent on using iframes for anything, then read the post mentioned.