HTML placeholder does not work for Android

I have a mobile version of my site and on the login page I use "placeholder" to display: Email or Password (instead of using 开发者_开发问答label).

For iPhone it's working but not for Android, it disabled my field css (borders, colors etc...)

Edit: I want to be able to use iPhone OS3, OS4 and Android 1 and 2

Why ?

Found it!

http://diveintohtml5.ep.io/forms.html

How to get rid of placeholder on password field taken over from label