could someone give me a some sort of clue about opening nonexistant files in VB.NET??

I am learning this as I go, and I can open existing files using the OpenFileDialog box, but I cant not find an real explanation on how to create a file if it is not in existance...

in other words, I want to know now to code so that when a user enteres a filename in the filename box in the OpenFileDialog and that file does not already exist then the file is created as a new file, and then opened.

I have done some googleing and found all sorts of examples on opening existing files, but nothing that really gives a good explanation of how to create a new file and then open it...

Cheers
Jeff