Something about <iframe> Back

There are 3 troubles in using <iframe>:

• <iframe> will block the event onload of the page.
• It's impossible for search engines to search contents from <iframe>, which make it hard to do Search Engine Optimization (SEO).

Solution: use JavaScript to set src for <iframe> dynamically.

• <iframe> will share Connection Pool (連接池) with pages, which will affect the loading of pages in parallel.