Function  13h   Delete File Via FCB                                       (FCB) 
      Deletes file specified in Struct -FCB from current directory
entry   AH      13h 
	DS:DX	pointer to address of Struct -FCB
return  AL      00h     file deleted 
		0FFh    if file not found or was read-only 
note 1) All matching current directory entries are deleted. The global filename  
	character "?" is allowed in the filename. 
     2) Will not delete files with read-only attribute set 
     3) Close open files before deleting them. 
     4) Requires Network Access Rights