Executes the Write procedure, then outputs an end-of-line marker to the file.
procedure Writeln([ var F: Text; ] P1 [, P2, ...,Pn ] );
Writeln is an extension to the Write procedure, as it is defined for text files. After executing Write, Writeln writes an end-of-line marker (carriage-return/linefeed) to the file. Writeln(F) with no parameters writes an end-of-line marker to the file. (Writeln with no parameter list corresponds to Writeln(Output).)
File must be open for output.