I'm trying to create new heading styles with numbering.

My heading numbering currently reads:

1 heading one


1.1 subheading one
1.2 subheading two

2 heading two
1.3 subheading one
1.4 subheading two

but i want them to read...

1 heading one
1.1 subheading one
1.2 subheading two

2 heading two
2.1 subheading one
2.2 subheading two

Please help! I've used multi-level lists but it hasn't solved the problem, anyone know what I'm doing wrong? Have I overlooked something?

TIA