title: "The modifier public is not valid for this item" on an Interface Method
body: <p>Okay, so I am having problems calling the method GetClassAverage() from the interfacce (the windows form displaying the data). I get the following error too 
  "The modifier public is not valid for this item"... this is the code on my IService.cs file</p>
  
  <pre><code>[ServiceContract]
  public interface IClassRollService
  {
      [OperationContract]
      List&lt;Student&gt; GetStudentList(int semester);
      [OperationContract]    
      double GetClassAverage(int anything);
  }
  </code></pre>
  
  <p>In my Service.cs file I have</p>
  
  <pre><code>public double GetClassAverage()
  {
      double sum = 0.0;
      double total;
      foreach (Student S in Students)
      {
          sum += S.Average;
      }
      return total = sum / Students.Count();
  }
  </code></pre>
  
  <p>On my windows form I fill a gridview by calling client.GetStudentList() but it does not work for GetClassAverage()</p>
  
  <p>What am I doing wrong or what am I missing?</p>
  
  <p>[EDIT] Already took out the public but I still can't call the method from the Windows Form. Is there any other way I can get the returned value from that method into to the windows form. This has something to do with the web services, that much I know.</p>