Getting node w/ lowest attribute value

Hi all.

I have some nodes like:

<addresses>
    <address IsActive="false" NumOrder=1>[...]</address>
    <address IsActive="true" NumOrder=3>[...]</address>
    <address IsActive="true" NumOrder=2>[...]</address>
</addresses>

How do I get the first address node where IsActive=true AND has the
lowest value for the NumOrder attribute?

In the above case I'd want the 3rd address node (IsActive="true" and
NumOrder=2).

Any assistance would be appreciated.  Thanks.