Question

How Can I open a web page from the As3 so that it replaces current iFrame (and Flash object).

Answer 1

Do you want to open the web page into the iframe or do you want to replace the whole page containing the iframe?

The former:

import flash.net.*;     navigateToURL( new URLRequest('url-of-the-page-to-be-opened'), '_self' ); 

The latter:

import flash.net.*;     navigateToURL( new URLRequest('url-of-the-page-to-be-opened'), '_top' );