Point to document.body of different html
<p>I am able to retrieve the the body pointed to current html page through <code>document.body</code> usage. Can anyone please suggest how to get the pointer to <code>document.body</code> of an other html page from the current one.</p>

<p>Example. I am currently in a.html. <code>document.body</code> gives a pointer for body of a.html. But I need a pointer to the body tag of b.html from a.html.</p>

<p>Can anyone please suggest the javascript command for the same</p>