Odata querry issue

    var lookupObject = Xrm.Page.getAttribute("msdyn_billingaccount");
	if (lookupObject != null)
	{
        var lookUpObjectValue = lookupObject.getValue();
        if ((lookUpObjectValue != null)) {
            var lookupid = lookUpObjectValue[0].id;
        }
    }
    var selectQuery = "/Account?&$filter=AccountId eq guid'" + lookupid + "'&$select=ap_Stopped, accountnumber";
	var oDataResult = null;
    //This is When my script fails
	oDataResult = MakeRequest(selectQuery);
	alert("Number = " + oDataResult[0].accountnumber + "\n" + "Stopped? = " + oDataResult[0].ap_Stopped);

function MakeRequest(query) {
    var serverUrl = Xrm.Page.context.getClientUrl();
    var oDataEndpointUrl = serverUrl + "/api/data/v8.0/";
    oDataEndpointUrl += query;
    var service = GetRequestObject();
    if (service != null) {
        service.open("GET", oDataEndpointUrl, false);
        service.setRequestHeader("X-Requested-With", "XMLHttpRequest");
        service.setRequestHeader("Accept", "application/json, text/javascript, */*");
        service.send(null);
        var retrieved = JSON.parse(service.responseText).d;
        var results = new Array();
//Here is where my Script Stops running.
        for (var i = 0; i < retrieved.results.length; i++) {
            results.push(retrieved.results[i]);
        } // End for
        return results;
    } // End if
    return null;
} // End function