Add subscription lightbox

Hello,
I’m using a child theme of twentyeleven, the url to my page is http://www.enlightenedinnergame.com.

I am also using getresponse as my autoresponder.

I want to integrate a subscription lightbox which shows up when people come to my homepage. I just want the lightbox to fade in, then ppl either subscribe or close the lightbox and then the whole homepage is visible again and they can go on browsing my page.

So I created the subscription form with getresponse (I made sure I selected ‘Lightbox’ and as effect ‘fade’ after 1 second) and have all the raw html code now, but unfortunately I don’t know where to put the code.

I tried putting it in different places within the welcome.php file as well as in different places within the homepage.

What happens though is, that each time the whole lightbox appears at whatever part I put it in and just stays there instead of fading in over the whole content.

I already have a permanent sign-up button in my sidebar, but I want to add a lightbox to the homepage that appears each time a new customer comes to the page.

If anyone could tell me where to put the code of the lightbox I would greatly appreciate it.

Thank you very much!