Handle on MSN Messenger's Sign In "button"?

I'm making a program that opens MSN Messenger, hits the Sign In "button", types in my info and hits OK. I have everything done(excluding the Sign In button part) but I can't get a handle on MSN's main Sign In button. I was just fishing for info by getting a handle on any of MSN Messengers child windows but it seems it only has one child window. This child window's class name, when GetClassName is used on it, turns out to be "DirectUIHWND". I have never heard of this kind of class name before. I'm guessing that this Sign In "button" isn't a button after all, just something acting as one? Why would Microsoft do this when making their IM program? What I just said might seem confusing but just read carefully. Thanks again.

Here is a picture of which button on MSN Messenger I am talking about.
http://img.photobucket.com/albums/v1.../msnbutton.bmp

You can download a version of spy++ here:
http://www.techwarelabs.com/download...on=file&id=169

It will allow you inspect windows of other processes a lot easier.

As for the "button" - it doesn't surprise me that it isn't a "Button" window class or even a window. For these kinds of controls, you can either simulate mouse clicking, mouse_event(), or you can get the handle to the "owning" window and post WM_LBUTTONDOWN etc... to simulate a mouse click.

gg

I got spy++ and spent some time looking through a whole bunch of MSN Messenger's classes. It has like 10 different classes. I also tried mouse_event but my program also LAUNCHES MSN Messenger so I don't think it's fully loaded by the time the mouse_event occurs, therefore the button is still not affected. Has anybody ever looked at MSN Messenger and know how you can manipulate that Sign In button in MSN Messenger's class called "DirectUIHWND". The name was confirmed by spy++. Thanks for the reply.