Getting an error when trying to place an order with Quantopian futures paper trade

Question

So I am now moving to learn quantopian for futures trading and have ran into a problem where I cannot place a paper trade. The error says that it cannot specify the symbol in the order method. I am hoping that someone can give me an answer to help me understand what is happening.

def initialize(context):  
    # Dow Jones E-Mini Continuous Future  
    context.future = continuous_future('YM')  
    schedule_function(daily_func, date_rules.every_day(), time_rules.market_open())

def daily_func(context, data):  
    ym_active = data.history(context.future, 'price', 50, '1m')  
    log.info(ym_active)  
    sma_50 = ym_active.mean()  
    sma_20 = ym_active[-20:].mean()  
    if sma_20 > sma_50:  
        #I am running into a problem where it says that I have to specify the contract.  
        order(context.future, 1, style=MarketOrder)  
    elif sma_20 < sma_50:  
        #I am running into a problem here too.  
        order(context.future, -1, style=MarketOrder)