How to make an enumerated list

[Ramón Flores d'as Seixas]

Hello:

     How can I do an enumerated list like the following one:


1. This is on item

     1.1. This is a subitem

     1.2. This is another subitem
           1.2.1 This is a subsubitem

     1.3  This is another subitem

2. This is another item    

3. This is another item

     3.1 This is a subitem



I want to put this list as part of the text. 


Thanks
    Ramón