ASP.Net - Call a function from inside an external cs source file

I've been struggling with what seemed like an easy task in asp.net/c# for longer than I would like. I thought this would be easy, since I understand the syntax of C/C++, JavaScript, VBScript, and VB.Net.

I have an aspx page and I would like to include a c# source file that defines and calls a function that uses HTTP Response. I do not want to have any of this code on the aspx page because there is no syntax coloring for c# embedded on an aspx page in Notepad++.

Any help would be appreciated. Here's some pseudo code to help you understand where I'm trying to end up:

test.aspx

<%@ Page language="c#" Src="test.cs" %>

test.cs

//Import
using System.Web.HttpContext.Current.Response;

//Define
public class myclass()
{
    public void myfunction()
    {

        Response.Write("Hello World");
    }
}

//Call
myclass::myfunction();

Also, do you -have- create an object from a class before accessing the members of it? C++ allows direct access to a classes' functions via the :: operator.

Tags: C#, ASP.NET, File