trying to insert data to Excel file using OLEDB

I want a button in c# form to be able to insert data to excel table.

this is what i did..

 try
             {
                 System.Data.OleDb.OleDbConnection MyConnection;
                 System.Data.OleDb.OleDbCommand myCommand = new System.Data.OleDb.OleDbCommand();
                 string sql = null;
                 MyConnection = new System.Data.OleDb.OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0;Data Source='C:\\Users\\Miko\\Documents\\WeightWatchers - Copy\\TrackingLoss.xlsx';Extended Properties=Excel 8.0;");
                 MyConnection.Open();
                 myCommand.Connection = MyConnection;
                 sql = "Insert into [Sheet1] (Date,Loss) values(y,x)";
                 myCommand.CommandText = sql;
                 myCommand.ExecuteNonQuery();
                 MyConnection.Close();
             }
             catch (Exception ex)
             {
                 MessageBox.Show(ex.ToString());
             }

when im trying it this window is open

anybody knows why and what to do?