How to show a ABOUT Form????????

Hello Everyone:
    I use C# want to Create a Project. In my project. there are two
forms. One is main form, and another  is a about form. In the about
form there are some information about my project. such as author's
information, product support and so on.
    Now, I add a button in the main form, I want that if the user click
the button. It will show the about form . In button's event . the code
like this:
    {
        about.show();
    }
    but it doesn't work, if in Delphi. It will be work.
    After that, I search the msdn. I know that there is a method called
AddOwnedForm(); so I coded the code like below:
    {
        Form cs =new Form();
                   this.AddOwnedForm (cs);
                   cs.Show();
    }
    This can show a new Form , but it is not the about form....
    What I should do? I'm very sorry for my English , I 'm from China.