When the options binding changes the set of options in your elements whenever the selection is programmatically changed. The dropdown is populated from the button click event outside the table. There’s nothing interesting about the view model here - this is just to make clear how bindings work with select elements, radio buttons, etc. I have button to add a row to table and then remove button against each row to delete it. This is very useful if you want to let the user select from a set of model objects. Use knockout's two-way data-binds instead of manually subscribing to UI events. By default, Knockout will prevent the event from taking any default action. Test your JavaScript, CSS, HTML or CoffeeScript online with JSFiddle code editor. In this case, the manual subscription acts like an asynchronous computed observable. My Issue: 1.) How to change your "Email Address ... 5:55. For examples of this, see Knockout has special support for drop-down lists (i.e.,