What is the function of the open file button on submit page of problems. ;

I am not quite able to what is its function
i tried uploading my code in it which was already accepted but it gave WA
because the code remained as template only and the file was not uploaded

if you have written your code in a file then if you use open file the code from the file will be displayed on the codechef IDE

but its not working in my case if i open any file .c or .txt nothing happens

It is still not functional.