semi-follow up to the MD issue

I need to remove a root directory, which may contain subdirectories. Recursion seemed the simplest solution:
1. Delete the files
2. Remove the subdirectories
3. Remove the root directory

FUNCTION RemoveDirectory
Parameters dirpath
Dele file (dirpath+"*.*")
entries = adir(aRemDirs,dirpath+"*.*","D")
If entries >= 0
for i = 1 to entries
If !Inlist(aRemDirs(i,1),".","..")
RemoveDirectory(dirpath+aRemDirs(i,1)+"\")
Endif
Next
Endif
RD (dirpath)
Return && RemoveDirectory

I read in the help that functions' parameters are passed by value, and i THOUGHT this would protect the scoping necessary for recursion. It's late on a friday, and while i can see this isn't working, i can't seem to figure out why.

I'm hoping someone will immediately see what i'm doing wrong. TIA