Simple class does not work

Hi everyone,
Why the following code (asp.net 1.1) does not work ?
Thanks,
May

//call.aspx
<script runat="server">
namespace DOTNETMath {
void Page_Load( Object s, EventArgs e )
{ 
     ConstClass.DisplayEmployee("Testing");
}
}
</script>
 
 
//commonFunction.cs

namespace DOTNETMath {

Public Class ConstClass {
  Public Shared Function DisplayEmployee(String x) {
  
    Return x + " Hello ";
  }
}
}
 
...