Retrieving data from xml table

Hi everyone,

I'm having trouble retrieving data from and xml database.

I want to retrieve only those columns where a condition is true, which is in SQL : SELECT name FROM customers WHERE age=21. I got my tables in a xml document, got my dataset and got a datagrid in my windows form. I can get the datagrid to show the whole table but I don't know how to do the equivalent to a SELECT command.

Thanks in advance.