Let's suppose I have blocks in my page.

The first block is for advertizement.
The second block is for contents.

When users visit the page in Safari, I like to make the page that safari's reader button in the address box of the browser is shown for the second block although the text in the first block is longer than the text in the second block.

The following is one for my trials, but failed.
<div id="1stBlock">advertizement</div>
<article id="2ndBlock">contents</article>