How to find a folder?

sub FindFile(Path as string)
fl = Files.ListFiles(Path)
for i = 0 to fl.size-1 
   if fl.get(i) = yoursubfoldername then
        yourpath = fl.get(i)
        return
   end if
   if file.IsDirectory(fl.get(i)) then
       FindFile(fl.get(i))
   end if
next
end sub

yourpath = ""
FileFile("/")

 Sub FindFolder(myPath As String, subfolder As String) As String

Dim fl As List
Dim i As Int
Dim p,f,r,dummy As String


  dummy=File.DirRootExternal 'Get sdcard Permission

  Log (mypath)  
  
  fl.Initialize
  
  Try
    'Listfiles throws Exception on some folders
    If mypath = "" Then
      fl = File.ListFiles("/")
    Else   
      fl = File.ListFiles(myPath)
    End If   
  Catch
    Return ""
  End Try
  
  'Listfiles returns null for some system folders
  If fl.IsInitialized = False Then Return ""
    
  For i = 0 To fl.size-1 
    p = mypath 
    f = fl.Get(i)
    Select p      'ignore some system folders
    Case "/dev"   
    Case "/proc"
    Case "/sys"
    Case "/system"
    Case Else
      If File.IsDirectory(p,f) Then
        If f = subfolder Then Return p  & "/" & f  '<--- success
        If File.IsDirectory(p, f) Then
           p = p & "/" & f
           p = FindFolder(p, subfolder)            '<---recursive search
           If p <> "" Then Return p                '<---success
        End If
      End If  
    End Select
  Next
  Return ""
  
End Sub