Declare and assign multiple string variables at the same time

You can to do it this way:

string Camnr = "", Klantnr = "", ... // or String.Empty

Or you could declare them all first and then in the next line use your way.

You can do it like:

string Camnr, Klantnr, Ordernr, Bonnr, Volgnr;// and so on.
Camnr = Klantnr = Ordernr = Bonnr = Volgnr = string.Empty;

First you have to define the variables and then you can use them.