Variation which reads in strings instead of assigning them.

	program exc;
	var
		x, y, t: string;
	begin
	readlnx(x);
	readln(y);
	writeln('x = ', x, ' y = ', y);
	writeln('exchange');
	t := x;
	x := y;
	y := t;
	writeln('x = ', x, ' y = ', y);
	readln;
	end.

Sample output:
<Diane
<Billy
>x = Diane y = Billy
>x = Billy y = Diane