ASP.Net MVC Error: must declare a body because it is not marked abstract, extern, or partial

Error must declare a body because it is not marked abstract, extern, or partial

#region Assembly DataLayerB, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
// D:\Project\Amlakeabdi\AmlakeAbdi\AmlakeAbdi\Bin\DataLayerB.dll
#endregion
 
using System.Data.SqlClient;
 
namespace DataLayerB
{
    public static class General
    {
        public static object ExecuteScaler(string spName, SqlParameter[] parameters);
        public static T ExecuteScalerB<T>(string spName, SqlParameter[] parameters);
        public static SqlCommand GetCommand(string spName, SqlConnection conn);
        public static SqlConnection GetConnection();
        public static SqlConnection GetConnectionSession();
    }
}

   private void BindTransfer1()
   {
       Ddlvagozari.Items.Clear();
       Ddlvagozari.Items.Add(new ListItem("All", ""));
       Ddlvagozari.AppendDataBoundItems = true;
       using (SqlConnection conn = General.GetConnection())
       {
           using (SqlCommand _cmd = General.GetCommand("selecttransfer1", conn))
           {
               _cmd.Parameters.AddWithValue("@Type", Ddltype.SelectedItem.Text);
              
               conn.Open();
               Ddlvagozari.DataSource = _cmd.ExecuteReader();
               Ddlvagozari.DataTextField = "Transfer";
               Ddlvagozari.DataBind();
           }
       }
   }