Closes a file that was opened using FOPEN.
A string, the name of the file to close.
A 1 if the close was successful; otherwise it returns 0.
closes myfile (an open file) and displays a 1 at the bottom of the screen if the close is completed successfully.
For all files which were opened with FOPEN, it is highly recommended to perform an FCLOSE or FCLOSEALL prior to exiting.