(I still feel like a complete newbie in MS Visual environments... so please bear with!)

I'm using Microsoft Visual C# 2008 Express Edition.

I have a project and in that project are two different forms. The .cs file for each form starts out:

```
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.Common;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace MyNameSpace
{
    public partial class MyFormName : Form
    {
...

```

(...and the second is "MyFormName2" but no differences besides that)

I want to write a function that I know both forms are going to need to access. I right-clicked on my project, selected "Add", selected "New Item" then selected "Code File" and named my file "Common.cs" and it gave me a completely blank file that's in my project.

How do I set this up...? I thought I should do the following...

```
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.Common;
using System.Drawing;
using System.Text;
using System.Windows.Forms;

namespace MyNameSpace
{
}

```

...but then when I try to add a function like:

public void mytestfunc() {
}
within that namespace I get the following error: 

"Expected class, delegate, enum, interface, or struct"

How do I set things up so I can have "mytestfunc" be available to both MyFormName and MyFormName2?

Thanks!

-Adeena

UPDATE:
Understand (now) that everything must be in a class, but then I don't understand how to really use it. Does that mean I have to create an object? This common function happens to just be some math... 

so now if I have this:

```
namespace MyNameSpace
{
    public class MyCommonClass
    {
        public void testFunc()
        {
            MessageBox.Show("Hee hee!");
            return;
        }
    }
}

```

...how do I call testFunc from my Form? Must I do the following:

```
MyCommonClass temp = new MyCommonClass;
temp.testFunc();

```

or is there another way to call testFunc?