Valid Delete Command - Creating A Form That Creates New Users And Then Updates Them To A Dataset

I am creating a form that creates new users and then updates them to a dataset, I have done this ok, but I am getting a runtime error when I delete a record. Please see below the exception being thrown

"Update requires a valid DeleteCommand when passed DataRow collection with deleted rows"

My code below

CODE:

So I know I need to add a delete command, but how do I write this in code and do I write it in the saveitem click event? I guess I would because the app crashes when I click save to update the dataset.