Sending data

Hi, i am tring to do the following:-

When a user opens a webpage, i want to send certain data to a server, without the user seeing like so :-

That would be what i need to send, i am not worried about errors and what not, i just need to be able to send this string to the server!

Is it possible without the user seeing it?

Regards
Jules

1) Cookie
2) <input type="hidden" name="var" value="xxxxx"> Not hidden perfectly, only into HTML code. :-(

Hope this helps