如何把下列排列组合程序改成递归调用的函数？求救!!!!!!!!

[mac]

procedure TForm1.Button2Click(Sender: TObject);
var
I,M:integer;
I01, I02, I03, I04, I05, I06, I07: integer;
begin
I:=5;
M:=36;
case I of
4:
for I01 := 1 to M do
for I02 := I01 + 1 to M do
for I03 := I02 + 1 to M do
for I04 := I03 + 1 to M do
begin
S := S + IntToStr(I01) + IntToStr(I02) + IntToStr(I03) + IntToStr(I04) + #13#10;
end;
5:
for I01 := 1 to M do
for I02 := I01 + 1 to M do
for I03 := I02 + 1 to M do
for I04 := I03 + 1 to M do
for I05 := I04 + 1 to M do
begin
S := S + IntToStr(I01) + IntToStr(I02) + IntToStr(I03) + IntToStr(I04) + IntToStr(I05) + #13#10;
end;
6:
for I01 := 1 to M do
for I02 := I01 + 1 to M do
for I03 := I02 + 1 to M do
for I04 := I03 + 1 to M do
for I05 := I04 + 1 to M do
for I06 := I05 + 1 to M do
begin
S := S + IntToStr(I01) + IntToStr(I02) + IntToStr(I03) + IntToStr(I04) + IntToStr(I05) + IntToStr(I06) + #13#10;
end;
end;
end;

[mac]

需要大家帮助！