Silverlight WCF problem

Question

I want codes of below points:
1.) I have created a method in WCF which returns not all but only some columns in tables.
2.) In silverlight control, I have 3 textboxes. And I want to return result tables column in these textboxes.

ex.  Table have 5 columns.
      But in WCF method, it returns only 3 columns.
      And result of 3 columns will display in 3 textboxes.