Cross site scripting forms

I want to help fill forms for my users with default values on other pages. To do that I would like to show another page (from different domain) in an iframe and insert there default values when needed into fields. But it is not possible because of cross site scripting protection.

I have checked http://sourceforge.net/projects/poxy/ and it almost works to view page through proxy but unfortunately not always. Is there 开发者_开发百科another way to do that? Ie.

How to connect to fields in the iframe? Is it possible?

AFAIK, You cannot access fields from another page like iframe. If you want to fill form by using JS, you can try to write Bookmarklet for your browser. That's a bookmark which executes javascript on current page.