Navigator 2.0, Internet Explorer 3.0
Document.writeln() behaves just like Document.write() except that after appending all of its arguments to document, it also appends a newline character. See Document.write() for more information on this method.
Newline characters are not usually displayed in HTML documents, so in general, it is only useful to use Document.writeln() when writing text to appear in a <PRE> or <XMP> environment, or when writing to a document opened with a mime type of "text/plain".