Call a web service from html page

Hi guys
I'm quite new about web services, I need create a html page that call a web services in a sepate domain.
The web services have as input an Image (I think a stream ??) and a simple string.
the form html should be able to send an image and a string to the web services and retrieve a boolean.

I use .net 3.5 and visual studio 2008 for the web service

Do you think is possible ? Please, and how can I achieve it ?

Thanks