Binding data to a ComboBox and then showing ValueMember in another TextBox
It looks pretty clean. As far as I can tell, you have a good separation of concerns. Everything is properly cased and your functions have verb-noun names. All good things. 

The only nitpick I have is the bs variable. I'm not a fan of ultra short names of any kind. You could call it source or some such thing. Seriously though, that's a huge nitpick. I just couldn't find anything else to comment on.