A string specifying the name of the file as recognized by the MobiLink server. This property has no default value, and must
be explicitly set.
FileName is the name of the file on the server running MobiLink. MobiLink first searches for this file in the UserName subdirectory
and then in the root directory (the root directory is specified via the MobiLink server's -ftr option). FileName must not
include any drive or path information so that the MobiLink server can find it. For example, "myfile.txt" is valid, but "somedir\myfile.txt",
"..\myfile.txt", and "c:\myfile.txt" are all invalid.