JSon Error

Hi,
i have lookup entity "Distribution list" that i display in custom entity "sms" in subgrid (N-N), also the "Distribution list" entity contain users from the systemuser entity (N-N).
-I can select more than marketing list
-I want when i select the Marketing list to execute JScript to get theur users and store them in sms entity's custom option set field.
-the code that i try is bellow, but nothing happen the code is bellow :

function storeDlistPhones()
 {
var gridControl = document.getElementById('DistributionList').control;
var ids = gridControl.get_allRecordIds();
for(i = 0; i < ids.length; i++)
    {
    var lisguid=gridControl.getCellValue('new_name', ids[i]);
       var serverUrl = Xrm.Page.context.getClientUrl();
       var oDataSelect =serverUrl + "/new_distributionlistSet?$select=new_new_distributionlist_systemuser/FullName,new_new_distributionlist_systemuser/MobilePhone&$expand=new_new_distributionlist_systemuser&$filter=new_name eq '"+lisguid+ "'";

  var retrieveReq = new XMLHttpRequest();
    retrieveReq.open("GET", oDataSelect, false);
    retrieveReq.setRequestHeader("Accept", "application/json");
    retrieveReq.setRequestHeader("Content-Type", "application/json;charset=utf-8");
    retrieveReq.onreadystatechange = function () {
        GetContactData(this);
    };
    retrieveReq.send();
}
}

function GetContactData(retrieveReq) {
    if (retrieveReq.readyState == 4) {
        if (retrieveReq.status == 200) {
            var retrieved = JSON.parse(retrieveReq.responseText).d; 
            varmessage=retrieved.results[0].MobilePhone;
           //---here i need to make a loop for the retrieved data count to store it in the option set-----------------
            Xrm.Page.getAttribute("new_smsrecipient").addOption(varmessage, 0);
        }
    }
}