Increase columns width in Silverlight DataGrid to fill whole DG width

Question

I have a DataGrid Control which is bound to a SQL Table.

The XAML Code is:

Answer 1

Tested only in WPF, not in Silverlight:

I set up in WPF 3.5 SP1 and it works perfect, no guaranties about Silverlight, but if it works it's indeed charming.