macromedia flash flash remoting: Hi,

I'm just discovered AMFPHP, and I have a very stupid question. I tried to
connect flash with mysql using remoting, and everything works great if I want
to display some data in a datagrid. Now, I'm trying to display just one field
inside a combobox and I have no clue about how I can accomplish that. If I set
the result of the call as teh dataprovider of a cb I get all the values from
all the fields inside the cb. So my question is how can restrict the result to
just one field and set that as the dataprovider?