I added a class called Matrix to my App_Code File folder. It runs and
compiles fine in the Visual Web Developer but when I try to view the
page in my browser I get the following error msg.

CS0246: The type or namespace name 'Mapack' could not be found (are
you missing a using directive or an assembly reference?)

using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;

namespace Mapack
{
   /// <summary>
   /// Summary description for Matrix
   /// </summary>
   public class Matrix
   {

       /// <summary>
       /// Class attributes/members
       /// </summary>
       int m_iRows;
       int m_iCols;
       // Fraction[,] m_iElement;

       /// <summary>
       /// Constructors
       /// </summary>
       /*  public Matrix(Fraction[,] elements)
         {
             m_iElement = elements;
             m_iRows = elements.GetLength(0);
             m_iCols = elements.GetLength(1);
         }*/

       /* public Matrix(int[,] elements)
        {
            m_iRows = elements.GetLength(0);
            m_iCols = elements.GetLength(1); ;
            m_iElement = new Fraction[m_iRows, m_iCols];
            for (int i = 0; i < elements.GetLength(0); i++)
            {
                for (int j = 0; j < elements.GetLength(1); j++)
                {
                    this[i, j] = new Fraction(elements[i, j]);
                }
            }
        }*/

       public Matrix()
       {
           //
           // TODO: Add constructor logic here
           //
       }
   }

}

I added using Mapack; to the page I am trying to use the class in but
I still keep getting the same error.