Validate Klarna form

[Krister.Johansson]

If I want to validate the Klarna checkout form when something changes let say email. And check if that user already exists. What is the best way to do this?
Litium version: 7.*

[Ericsj11]

You can use this in the javascript if you need to validate while the user is typing:

if (window._klarnaCheckout) {
    window._klarnaCheckout(function (api) {
                        api.on({
                            'change': function (data) {
                                if (data.email) { 
                                }
                            }
                        });
                    });
                }