Here is an article I found that explains how to nest your data. It is for the datarepeater but the same concepts hold true for datalists.

http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q306154&ID=KB;EN-US;Q306154&&FR=1

>>To get this look you would use a nested DataList for the child data inside of a DataList.
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>I suppose that I have to use GetChildRows() in order to the child DataList display just the related records. Where do I put GetChildRows()?
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>Thank you.
>
>Eugenio