Hello,
I am using your combobox in my project (typical web 2.0 client-server application). The generated HTML sources doesn't contain the <!DOCTYPE> used in your example.html. there are some historical reasons why i cannot use DOCTYPE (but i know that webdevelopers should use it).
Please have a look on this picture http://imageshack.us/photo/my-images/38/combobox.png/
it displays your example.html from github. the only differences are that i removed the DOCTYPE tag and added an
after Field1. Can you extend your combobox so that it will work without the DOCTYPE tag too?