以下为程序，求解为何蓝色线无法显示出来，求指教
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//+------------------------------------------------------------------+
//|                                    MA System.mq4 |
//|                                     Philip Hall |
//|                                         APP |
//+------------------------------------------------------------------+
#property copyright Philip Hall
#property link      APP
#property version    1.00
#property strict
#property indicator_separate_window
#property indicator_buffers 2
#property indicator_color1 Red
#property indicator_color2 Blue
#property indicator_width1 2
#property indicator_width2 2
//指标参数设置
input int MA_1=5;
input int MA_2=8;
double MASystem_1[];
double MASystem_2[];
//+------------------------------------------------------------------+
//| Custom indicator initialization function                  |
//+------------------------------------------------------------------+
int onInit(void)
 {
 IndicatorDigits(Digits+1);
//--- indicator buffers mapping
 SetIndexStyle(0,DRAW_LINE);
 SetIndexStyle(1,DRAW_LINE);
 SetIndexDrawBegin(0,MA_12);
 SetIndexDrawBegin(1,MA_12);
 SetIndexBuffer(0,MASystem_1);
 SetIndexBuffer(1,MASystem_2);
//---
   return(INIT_SUCCEEDED);
 }
//+------------------------------------------------------------------+
//| Custom indicator iteration function                     |
//+------------------------------------------------------------------+
int onCalculate(const int rates_total,
            const int prev_calculated,
            const datetime time[],
            const double open[],
            const double high[],
            const double low[],
            const double close[],
            const long tick_volume[],
            const long volume[],
            const int spread[])
 {
 int i,limit;
 limit=rates_total-prev_calculated;
 if(prev_calculated 0){limit++;};
 
 for(i=0; i limit; i++)
 
 
 MASystem_1[i]
 =iMA(NULL,0,MA_1,0,MODE_EMA,PRICE_CLOSE,i);
 
 MASystem_2[i]
 =iMA(NULL,0,MA_2,0,MODE_EMA,PRICE_CLOSE,i);
 
//---
   
//--- return value of prev_calculated for next call
   return(rates_total);
 }
//+------------------------------------------------------------------+
//| Timer function                                   |
//+------------------------------------------------------------------+
void onTimer()
 {
//---
   
 }
//+------------------------------------------------------------------+