When you write a textual region to a file without using the keywords destructive or append, ESL creates a new file; for example:

write Manual to file "ARCHIVE.DAT"

If a file with the name ARCHIVE.DAT already exists, or if for any other reason the operating system does not let ESL create a file by that name, then ESL does not perform the operation. An error message is generated and the value of ioerror is set to true.