How to automatically display keyboard for textfield on page?

How to automatically display keyboard for textfield on page?

Hi,
I've got a page with only a textfield on and I want the focus to be set on the textfield and the keyboard on the iPhone to be displayed once the page is flipped. Any ideas on how to solve this?
I've tried the 
$("#textField").focus();
but the keyboard is not visible by default.

Thx,
VTM