c# - Upload files to a specific folder in dropbox -

i using example upload files dropbox:

http://cgeers.com/2012/03/11/dropbox-rest-api-part-5-file-upload/

which is:

public filesysteminfo uploadfile(string root, string path, string file) {   //... } 

the method has 3 parameters:

root: root relative path specified. valid values sandbox , dropbox.
path: path file want upload.
file: absolute path local file want upload

call method follows:

var file = api.uploadfile("dropbox", "photo.jpg", @"c:\pictures\photo.jpg");   

dropbox api says same example:

https://www.dropbox.com/developers/core/docs#files-post

so no mentioning of "parent folder"..
how can upload files under specific folder instead of root?

cant do

var file = api.uploadfile("dropbox", @"myfolder\photo.jpg", @"c:\pictures\photo.jpg");