Validating directory and file

Hello All,

I want to check if user had input correct directory or a file name. I mean, if user type in wrong directory, for example, instead of typing "c:\file.txt", if they type "z:\file.txt"

I should let the user know that the file or directory does not exist. Is there any FM for that? Please let me know.

Secondly, is there any way I can write down the field names of my internal table while try to download the internal table to a txt file. How can i get this info in my txt file from my internal table. Right now, I can only download the content of my internal table to a txt file, without field headings. Any help would be great.

Thanks in advanced!