{ Read the file INCLUDE to learn how to include this file in your program }

const
	SYMBOLLEN = 20;		{length of string}
	BLANKS = '                    ';
type
	symboltype = array[1..SYMBOLLEN] of char;

procedure GetSymbol (var identifier:  symboltype);
{Get the next identifier.  Return blank if there aren't any left.}
var
	index:  integer;
	c:  char;
	continue:  boolean;
	ALPHANUMERICS: set of char;
begin
	ALPHANUMERICS := ['a'..'z','A'..'Z','0'..'9'];
	{Find start of identifier.}
	continue := true;
	while not eof and continue do begin
		read(c);
		continue := not (c in ALPHANUMERICS)
	end;
	{Build identifier.}
	identifier := BLANKS;
	index := 1;
	continue := true;
	while (c in ALPHANUMERICS) and continue do begin
		if index <= SYMBOLLEN then begin
			identifier[index] := c;
			index := index + 1;
		end;
		if not eof then begin
			read(c);
		end else begin
			continue := false;
		end;
	end;
end;