Automatically Shipment Costs &MORE..

Automatically Shipment Costs &MORE..

1. When I enter the customer's name, if they are not registered, it should display an alert that the customer is not registered. 2. If I find the customer when I select them, it should check if they have any other orders for the current week. If they do, it should display an alert that there is a 'Sammelbox.' 3. If there are no other orders, it should then check the billing country of the customer. If it's 'Land Deutschland,' it should automatically add 'Versand 6 Euro.' If it's from any other European country, it should be '16 Euro.' If it's outside Europe, it should be '25 Euro.'
How Can I do This?