import external classes

Hi. I'm really new in the .net world and I would like some help with this problem.

When I did some programming in PHP did I use to put classes in separate files so I could use the classes for diffrent applications.

Is this possible with C# and how would a simpel code look like

I would be really greatfull for some code, pointers in rigth direction or a direct link to some tutorial for this issue.

Se below for description how I mean (my example is not real code!!!).

Br

Mattias Nyqvist

-----

file.1 (Not real code!!)

class fileOne

{

string message= "hello world";

}

file2.(not real code!!)

namespace mainApp

{

class mainApp

{

public static void main(){

newclass = new fileOne;

console.writeline( message);

}

}

}