NSArrayController , arrangedObjects and tableColumn IB connection

I am new to mac development. I am trying to make this app from apple.com

At one point i am stucked in interface bu开发者_StackOverflowilder.

How do i connect arrangedObjects.firstName to the Value - Table Column - First Name and Last Name?

Edit:

this is my array controller and its bindings.

Thank you in advance..!!

Ctrl Shift click with a mouse on a column in your table (NOT column's header). You should see the list of views which are parent to each other:

Select NSTableColumn view. Then just open bindings tab and perform same procedure as with arrangedObjects' binding.