although I can easily stick a bitmap image on a plane using the Material Editor, I am not able to do the same with a movie (either .avi or . mpg). I would very much appreciate if someone could let me know the method. Thank you in advance.
what you are asking for should not give you any problem.. in 3dsmax any texture can be both a movie or an image file, so you just take the exact same procedure.
this means you just need to use a Bitmap on your material component, both if you want to use an image or a movie file
In between my question and your answer I hvae made several tests and it turns out that I have succeded to use amovie as a texture for a plane using avi files. The Mpeg's files that I had used didn't work. Thank you for your help.