Parts and Sections numbering

[Matt Williams]

Dear List,

A (hopefully) simple question:

Using Lyx, how do "re-start" the numbering of sections for different
parts?

viz:

Part 1:
        Secn 1
        Secn 2
        Secn 3

Part 2:
        Secn 1
        Secn 2

Part 3:
        Secn 1
        Secn 2

Thanks for your help,

Matt