Two way data binding for controls

Question

Hi, I have a textbox and a listbox (on separate forms), I've set the datasource of the listbox to be a class that contain a bindinglist<string> which is populated by the textbox, making it so I can type in the textbox and populate the listbox.

What I'd like to also do is make a binding in the other direction at the same time, I want to click on an item in the listbox and have that text be shown in the textbox, thereby having a two way bind between the controls.

 

Could someone tell me how that is done please?

Thanks