How can we specify categoryid to get the required categories.Let say if we have 4 categories inside a Album

<album id="AlBum" name="(Default Album)" nextcategoryid="5" lastPhotoTime="2009-11-23 18:46:30">

<category id="1" />

<category id="2" />

<category id="3" />

<category id="4" />

</album>
 
How can we display only category 2 and 4.
 
Thnaks & Regards
Sekhar