autofocus with keyboard in an ipad html5 site

Question

I'm working on an html5 app that will be used on iPads in a kiosk mode. The first thing users must do is sign in, so when the homepage loads, I'd like the onscreen keyboard to popup with the focus in the first field.

I've tried all the variants I can think of, including

• html5 <input autofocus> attribute
• calling document.getElementById("nameFirst").focus() in window onload
• same as the previous, but the onload calls a timer method to invoke the focus call later

Has anyone figured out how to make the keyboard automatically appear?