jQuery Grid Plugin - jqGrid

Hi All,

In the Add Record dialog i was able to populate a combox with values returned from a WebMethod, using the editoptions { value: array} however I would like to be able to use the dataUrl and buildSelect in order to be able to specify the ID in the select list. The issue i'm having when using the dataUrl is that also the request is being done, and data returned accordingly, i'm unable to access the data. Below is my code:-

                   { name: 'FirstName', index: 'FirstName', width: 90, editable:true, edittype: 'select', stype: 'select',
                    editoptions: {
                        dataUrl: 'DataServices/DataServices.asmx/GetFirstNames',
                        buildSelect: function (data) {

                            
                            var requestData = data.d

                            $.each(requestData, function (index, value) {

                                console.log(value.FirstName);
                            });
                            
                        }
                   }},

That is returning an undefined object. Any idea please cause this issue have been driving me crazy? The reason i would like to use the dataUrl instead of the value option, is that when i want to add a record, the data sent to the webmethod for firstname is the ID of the option which is generated when the select is generated.

Thanks