A Web-based invoice viewing system and method for enabling a customer to generate invoices relating to various network services provided to the customer by an enterprise. This precursor has at least two laser-engraveable layers, in which the underlying non-printing laser-engraveable layer is more sensitive than the outermost non-metallic printing laser-engraveable layer. of mixture for every 50 litres of water, using proportional measures to obtain different amounts, being characterised by the fact that the composition of the powder mixture includes a mixture of various plant extracts. A second operation is performed using a charge stored in the second charge pump as a result of charging the second charge pump. Here, at the contact point between the coupling element and the component to be coupled, a force acting on the coupling element during coupling is introduced at an angle relative to the coupling direction of the coupling element. The object can be electrically conducting, dielectric or magnetic.