How do you use classes that are in seperate files !?

Question

I"m new to C#. Something that is really easy in Java & C++, I can't seem to get it work in C#. When you make a class yourself in Java, you create a file called for example "File1.java" when you compile this it gets compiled in to a file called "File1.class" Lets say I want to make an object of a class that is in "File2.class" In "File1.class" You will have to define: Import File2.class; // The only condition is that both classes have to be in the same directory. After that you can start making objects of the File2 class. What I've learned from C# is that it is NOT necessary for the class name to have the same name as the file name. In C++ you would just simply write: #include "File1.h" // The name of the header file... Right now I'm using ASP .NET with C#. In my "example.aspx" file I have: <%@ Page inherits="File1" src ="CodeBehind.cs" %> In my "CodeBehind.cs" file I have: using System; using myown; public class File1 : Page { //Here I want to make an object of the second class "File2" that is in a seperate file ! I called the second file "SecondFile.cs" namespace myown; public class File2 { // Definitions of properties, methods, fields, and events. } MY QUESTION IS: HOW DO I TELL THE "CODEBEHIND.CS" FILE THAT IT HAS TO LOOK IN "SECONDFILE.CS" TO FIND THE CLASS "FILE2" This shouldn't be very hard !???? Anybody HELP !?