ASP.Net GridView RowUpdating not working

Hi! I used below code but not update table. I want used gridview update. 

protected void Grid_RowUpdating(object sender, GridViewUpdateEventArgs e)
{
      string nm = ((TextBox)Grid.Rows[e.RowIndex].FindControl("TextBox1")).Text;
      string pr = ((TextBox)Grid.Rows[e.RowIndex].FindControl("TextBox2")).Text;
      string kod = ((TextBox)Grid.Rows[e.RowIndex].FindControl("TextBox3")).Text;
      Grid.EditIndex = -1;
      //service.Tool_chengeil(nm, pr, kod);
      SqlConnection con = new SqlConnection(UserData);            
      SqlCommand cmd = con.CreateCommand();            
      cmd.CommandText = "update underspb set idb = idb, nameb = N'" + nm + "', price ='" + pr + "' where id ='" + kod + "'";            
      con.Open();
      try
      {
         cmd.ExecuteReader();
      }
      catch { };
      con.Close();
}

When I used stored procedure it’s worked without problem. But I want use it’s in under grid view update because I have Unicode characters must used N prefix. In bellow I show sql table.

 Stored procedure:

CREATE PROCEDURE UPDIL 
@ID INT,
@NAME NVARCHAR(200),
@PRICE FLOAT
WITH ENCRYPTION
AS
UPDATE UNDERSPB
SET IDB = IDB,
NAMEB = @NAME,
PRICE = @PRICE
WHERE ID = @ID