Asp.Net Website giving error when upgraded my server from 2.0 to 4.0
<p>This code is working fine on my local computer which has Visual Studio 2010 and it was 
working fine on .NET Framework 2.0  but when I upgraded my server from 2.0 to 4.0 
it is giving this error:</p>

<blockquote>
  <p>Server Error in '/' Application.</p>
  
  <p>Compilation Error</p>
  
  <p>Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.</p>
  
  <p>Compiler Error Message: CS0246: The type or namespace name 'staticpage_namespace' could not be found (are you missing a using directive or an assembly reference?)</p>
  
  <p>Source Error:</p>
  
  <p>Line 10: using System.Web.UI.HtmlControls;</p>
  
  <p>Line 11: using System.Data.SqlClient;</p>
  
  <p>Line 12: using staticpage_namespace;</p>
  
  <p>Line 13: </p>
  
  <p>Line 14:    </p>
</blockquote>

<p>Can any any body help? </p>

<p>Here is the code which i am using for class in  App_code folder:--</p>

<pre><code>namespace staticpage_namespace
{       
  public class Staticpage
    {
    ......  
     public SqlDataReader InsertHome()    
        {
          SqlDataReader dr = SqlHelper.ExecuteReader(configclass.DbConn, CommandType.StoredProcedure, "InsertHome");

            return dr;
   }


        public Staticpage()
        {
            //
            // TODO: Add constructor logic here
            //
        }
    }
}
</code></pre>

<p>And this is the code for my webform:-</p>

<pre><code>using staticpage_namespace;


public partial class _Default1 : System.Web.UI.Page    
{ 

}
</code></pre>
