Triggring Event on an element of a dynamically generated iframe

Hello friends,
I want to trigger click event on an iframe's element through the main window, Doing it both ways, with or without jquery, will be usable for me. Basically, what I want to do is, I have developed a website http://www.ipjugaad.com, and on every document download page, I have placed an fb like button, what I want to do is that the like button should be automatically clicked when a user click on download button on my website. Give me some idea about how to do it?

Join it with the onclick event??

Yes but how can I access the element of that iframe in my code? That is my question.