merging avi files

i have 2 avi files, source1.avi and source2.avi.

After processing source2.avi, i wish to append it as source1.avi. but my code dun seems to work:


nFilenum = FreeFile
Open Source1 For Binary Access Read Lock Read Write As _ #nFilenum
ReDim Buffer(1 To LOF(nFilenum))
Get #nFilenum, , Buffer
Close #nFilenum

nFilenum = FreeFile
Open Source1 For Binary Access Write Lock Read Write As _ #nFilenum
Put #nFilenum, , Buffer
Close #nFilenum

anyway, is it possible to merge the avi files together using binary access in the first place or do i have to process frame by frame? dun laugh .... i am quite newbie to programming...:(