right-sidebar tablet

My website is www.casino-online.bz
On my right sidebar I have an iframe that contains all the banners. Such banners are retrieved from external websites, for this reason I cannot create a module for any banner (too much time to render the page).
There is only one module that contains the right-sidebar-iframe and it has such html code:
<iframe width="310" height="3200" frameborder="0" scrolling="no" src="/advertising/rightsidebar-casino.php"></iframe>

If I watch the website by a desktop pc everything is good, but when I watch the home page by a tablet the right sidebar disappear from the right column layout and change position going down, so I have at the bottom one long column like this one:

tablet-unixy.jpg

Is there a way to have a better layout so the right-sidebar banner images can fill out all the (empty) space at the right?

With iframe I'm afraid it cannot be done. RWD + iframes doesn't work well.

I think a solution could be detect it is a tablet and then serve the same iframe but with a different width.
Do I have a variable or "something" that says to me that the visitor is using a tablet?

You might try using css @media queries:
http://css-tricks.com/css-media-queries/
If you will come to something that actually works, and some small fixes will be needed, please let me know.

I couldn't use your link because I do not know height of the iframe. Sometimes I have 11 banners, sometimes 9 banners, ... depending of the category where I am.
I solved in this way:
instead of having one iframe inside one custom html module I splitted the iframe in two iframes and created 2 custom html modules.
Having 2 modules implies that 50% of banners go on the right of the first iframe.
Tested with all resolution seems working pretty good.

Brilliant idea. I thought splitting was not an option. I'm glad you could solve it out .