Put Data from a table to a label

Hello, i have this code


Saludos, tengo el siguiente codigo.

  SqlDataSource sds = new SqlDataSource();

        sds.ConnectionString = ConfigurationManager.ConnectionStrings["DatabaseConnectionString2"].ToString();

        sds.SelectParameters.Add("username", TypeCode.String, this.username.Text);
        sds.SelectParameters.Add("password", TypeCode.String, this.password.Text);
       

        sds.SelectCommand = "SELECT * FROM [Descuentos] WHERE [ID_DIM] = @username AND [Password] = @password";
        
         
          DataView dv = (DataView)sds.Select(DataSourceSelectArguments.Empty);

          try
          {
            if (dv.Count == 0)
            {
              this.lblinfo.ForeColor = System.Drawing.Color.Red;
              this.lblinfo.Text = "Numero de DIM o Password incorrecto!";
              return;
            }


The Table has the next Values: ID_DIM, Nombre, Descuento and Password, i make a comparation between the DIM and Password in the database (user and pswd), now i need the "Descuento" (discount)  value into a label, to make an arithmetic operation.

For example, if i am the DIM number 5689, and i have the 35% of discount, put the 35% into the label to make the operation.

any suggestion i will apreciate it (by the way, sorry about my english).