HELP: How do I get the Size of a Movie (avi) I opened in an OpenFileDialog?

Im trying to code a media player from scratch and I noticed that the Movie I play will always stretch out to my moviewindow size Ruining the aspect ratio--I want to get the size of the original File, and make it work alwasy have that aspect Ratio...I cannot get the size,

Thanks
-Lobster Productions
http://lobsterproductions.weebly.com/

By size what do you mean?
Bytes or?

Dim f As New IO.FileInfo(FilePath)
Dim size As Integer = CInt(f.Length)
msg(size)

Resize after loading. The mediaplayercontrol has two properties. ImagesourceHeight imagesourceWidth.

Load the movie then resize the window acording to the info.