Program with procedure to find volume of cylinder.

	program vols;
	var
		r, l, v: real;
	procedure cylvol(var radius, leng, vol: real);
		var
			pi, endarea: real;
		begin
		pi := 3.14159265;
		endarea := pi * radius * radius;
		vol := endarea * leng;
		end;
	begin
	writeln('radius ? ');
	readln(r);
	while r > 0.0 do
		begin
		writeln('length ? ');
		readln(l);
		cylvol(r, l, v);
		writeln('The volume of the cylinder is ', v:10:2);
		writeln('radius ? ');
		readln(r);
		end;
	readln;
	end.

>Sample output:
>radius ?
<1.0
>length ?
<10.0
>The volume of the cylinder is      31.42
>radius ?
<10.0
>length ?
<1.0
>The volume of the cylinder is     314.16
>radius ?
<0.0