CRM 2013, C# PlugIn - FetchXML

Hi 

I have the following code that is getting data from my grid and exporting to a CSV file;

string fetchxml = @"<fetch mapping= 'logical'><entity name ='product'><attribute name = 'name'/></entity></fetch> ";
EntityCollection result = service.RetrieveMultiple(new FetchExpression(fetchxml));foreach(var c in result.Entities)
  {
     if (result != null && result.Entities.Count > 0)
       {
         List<string> _product = new List<string>();
         foreach (Entity _entity in result.Entities)
           {
             _product.Add(_entity.Attributes["name"].ToString());
           }
string CSVFile = string.Join(",", _product.ToArray());
string AddressPath = "FM-OR" + "_";
string AddressSavePath = @"\\fm\CRMdata\maesteg\" + AddressPath + ".csv";

System.IO.File.WriteAllText(AddressSavePath, CSVFile.ToString());
}
}

My problem is that my fetchXML is returning all the items in product not just the selected ones in the grid, does anyone know how to stop this? 

Thanks, Shaun

S.Harrison