You've asked this question before, and so far have shown nothing to indicate that you've made any attempt to solve the problem by using the tools available to you. Like the functions palette. Or the search tool, since this question has been asked many times before.
Have you looked in the File I/O palette? There's the New Directory function for creating directories. There the File/Directory Info function that can be used to check if the folder exists (call the function, and if you get error 7 you know the folder doesn't exist). You can also use List Directory on the parent directory.
Make an effort.
