MSCRM2011用JS获取实体ObjectTypeCode

function getObjectTypeCodeByName(entityName)
{
    try
    {
        var lookupService = new RemoteCommand("LookupService", "RetrieveTypeCode");
        lookupService.SetParameter("entityName", entityName);
        var result = lookupService.Execute();
        if (result.Success && typeof result.ReturnValue == "number")
        {
            return result.ReturnValue;
        }
        else
        {
            return null;
        }
    }
    catch (e)
    {
        alert("Error while getting ETC by Name." + e.description);
    }
}