Simple image & retina image in one img

Question

I have this code:

<a href="/smi" class="media-link">
      <img src="/images2/smi.png" alt="About">
</a>

smi.png - it's simple image

I have smi2.png - it's retina image

How can I set two images in this code?

Answer 1

<a href="/smi" class="media-link">
    <img src="/images2/smi.png" srcset="/images2/smi2.png 2x">
</a>

http://www.w3.org/html/wg/drafts/srcset/w3c-srcset/