i am using the VB2008 IDE for C#.

my question may seem very basic but the solution is eluding me due to my lack of underastanding of classes and OOP programming i think.

i am using the following code on Form1.cs

Code:
private void button2_Click(object sender, EventArgs e)
        {
           textBox1.Text = Convert.ToString(addit(10, 21));
        }
and have a new class.cs page with the following in it

Code:
namespace WindowsFormsApplication1
{
    public class AdderClass
    {

        public int addit(int x, int y)
        { 
            return (x + y);
        }

        public int subit(int x, int y)
        {
            return (x - y);
        }

        public int multit(int x, int y)
        {
            return (x * y);
        }

    }
}

why is the IDE saying that the name "addit" does not exist in the current context on Form1.cs ?

they both appear in the same namespace although on different code sheets.

i now this is something really simple that i am not getting the grasp of but it has eluded me up to now.