Problem with my OData and javascript code...

Hi, my OData and Javascript seem to be failing here. Towards the end of the alert I receive an "Object Object" alert. Essentially what I am trying to do is this:

I have a Lookup attribute in Phone activity entity called "new_billtype" which looks up a record from an entity I created called: Timesheet. When I lookup a timesheet record, I also want to automatically add the value held in "new_rate" field (also in the timesheet entity) and insert it back into the Phone Activity record in the field "new_charge". The problem I have is the code below works until the end where I get an alert that says "Object object". 

Any help to fix this mess will be very appreciated. 

function getBillDetails()
{
    var lookUpObjectValue = Xrm.Page.getAttribute("new_billtype").getValue();
    if ((lookUpObjectValue != null))
    {
        var lookuptextvalue = lookUpObjectValue[0].name;
 
        var lookupid = lookUpObjectValue[0].id;
        
        alert(lookupid);
 
 
    var serverUrl = Xrm.Page.context.getServerUrl();
 
    //The XRM OData end-point
    var ODATA_ENDPOINT = "/XRMServices/2011/OrganizationData.svc";
 
 
    var odataSetName = "wse_timesheetSet";
 
    var odataSelect = serverUrl + ODATA_ENDPOINT + "/" + odataSetName + "(guid'" + lookupid + "')";
 
    alert(odataSelect);
 
    $.ajax({
        type: "GET",
        contentType: "application/json; charset=utf-8",
        datatype: "json",
        url: odataSelect,
        beforeSend: function (XMLHttpRequest) { XMLHttpRequest.setRequestHeader("Accept", "application/json"); },
        success: function (data, textStatus, XmlHttpRequest) {
 
            var result_service= data.d;
           
            
                        var ratevar = result_service.wse_name;
                        
                        alert(ratevar);
                        
                        Xrm.Page.getAttribute("new_charge").setValue(ratevar);

        },
        error: function (XmlHttpRequest, textStatus, errorThrown) { alert('OData Select Failed: ' + odataSelect); }
    });
 
    }
 
   }