text font size scale

text font size scale

Hi,
I
m using the following header in my HTML:
<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, maximum-scale=2.0, user-scalable=yes"; >

However, in my App (on iphone or ipad) i cannot enlarge or zoom the text (you know with the 2 fingers), the dimmension of the page is always fixed.

am i miss something?

thanks