Implement repository with ADO.NET and linq

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C#5.0

repository

ASP.NET4

I want to implement Save Operation(Insert/Update) as follow:

Emp n = new Emp();
n.Srl=1;
n.Name = "Mathew";
n.Save();

I should pass entity as the parameter to save Function and it's run correctly but really Ugly!!!... example: n.Save(n)

Model Class :

public class Emp :Classes.Repository<Emp>
   {
       private int srl;
       public int Srl
       {
           set { srl = value; }
           get { return srl; }
       }

       private string name;
       public string Name
       {
           set { name = value; }
           get { return name; }
       }

   }

public class Repository<T> : IRepository<T> where T : class
  {
      public SDataAccess Conn { get; private set; }
      public void Save(T entity)
      {
          if (entity == null)
          {
              throw new ArgumentNullException("entity", "Add to DB null entity");
          }
          //extention Methods
          var res = Conn.Save(entity);
      }

      public IEnumerable<T> GetAll()
      {
          throw new NotImplementedException();
      }



  }

What I have tried:

I implement Save Function in DAL Library as Follow way :

for Example :
Emp a = new Emp();
when calling New Keyword, I call Insert Function else Update Function
and correctly Run.