i want to change the layout of adsense ads as shown in some bigger sites like ezines or gmail itself... if anybody has the information about that kindly share....
In order to customize your adsense, you have to have HUGE traffic. If you are one of those big boys, google will contact you and let you know that you can customize. I get over 150,000 hits to my sites monthly and I'm no where near being able to customize adsense.
You need to be a premium publisher to use that code. I believe that Google doesn't even consider asking you to become a premium publisher until you have at least 20 million impressions per month. You should only use code that's generated through your own account - using modified code with your publisher ID can get your account disabled.
It sucks that you have to have more visitors than the populations of certain countries just to be able to make your ads look good so they can convert better. Current AdSense formats all look like they were designed in the 90s and will have a negative psychological impact on your visitors. In addition to customization, AdSense Premium also comes with private consultation. As of March 4 2013, however, Google opened up private consultation to anyone earning more than $25 a week (check the Inside AdSense blog). Hence, I urge all of you to contact Google and ask them to also open up customization to anyone earning more than $25 a week (or better, to anyone regardless of income). I think if we all do it, Google will eventually listen. Thanks!