>Hi all, i have this app installed on reception, here the person write the id of the visitor to register the visit. The code was wrote on ASP.net and C#, now i need to add the posibility of capture the face of the visitor using a pc cam. I need to do this by web to keep the person on same screen. Please help!!!
>T.I.A.

You can use Windows Image Acquisition(WIA) service. A COM component for WIA is free for downloading at microsoft.com.
http://channel9.msdn.com/coding4fun/articles/Look-at-me-Windows-Image-Acquisition

Also, did you already look at these:
http://www.codeproject.com/KB/dotnet/wiascriptingdotnet.aspx
http://www.codeproject.com/KB/cs/Face_Detection_processing.aspx
http://askernest.com/archive/2008/05/03/face-detection-in-c.aspx
http://friism.com/webcam-face-detection-in-c-using-emgu-cv
http://stackoverflow.com/questions/4953211/how-do-i-capture-video-from-a-webcam
http://www.codeproject.com/KB/audio-video/cameraviewer.aspx
c++
http://www.codeproject.com/KB/audio-video/face_detection.aspx

--> Thank you very much, this is helping me a lot!! Have a nice day