Why doesn't autofocus=“autofocus” work in Mozilla Firefox?

Question

<INPUT TYPE=TEXT NAME="Gw" MAXLENGTH="225" size="42" autofocus="autofocus">

If I try this with Google Chrome it works. I just want to highlight a form without <script>.

Why doesn't it work?

Answer 1

It should work in Firefox 4. But if you're using an older version of Firefox it won't work as the autofocus attribute is new to HTML5 which only gained broad support in Firefox 4..

Answer 2

It's wise to use autofocus with a JavaScript fallback for browsers that don't support it. From Mark Pilgrim's Dive into HTML5 Forms:

What’s that? You say you want your autofocus fields to work in all browsers, not just these fancy-pants HTML5 browsers? You can keep your current autofocus script. Just make two small changes:

1. Add the autofocus attribute to your HTML markup
2. Detect whether the browser supports the autofocus attribute, and only run your own autofocus script if the browser doesn’t support autofocus natively.

<form name="f">
  <input id="q" type="text" name="Gw" maxlength="225" size="42" autofocus>
  <script>
    if (!("autofocus" in document.createElement("input"))) {
      document.getElementById("q").focus();
    }
  </script>
  <input type="submit" value="Go">
</form>

Live demo here.