Start with a listview, two text boxes and a command button on a ASP.NET form
Add some code in the load event to create a Dictionary and store it in the
session object if the request isn't a post back.
Add come code to the command button click event to add the values to the
dictionary in the session object.

You will need some code to feed the list view with values from the
dictionary.

Post back where with your attempt at it for further help.