Alert freezes my mt4

#property indicator_chart_window
#property indicator_buffers 2
#property indicator_color1 White
#property indicator_width1 1
#property indicator_color2 White
#property indicator_width2 1

 int barsLeftOfCurrent =25;
 int barsRightOfCurrent = 25;
 int Arrowup=110;
 int Arrowdown=110;
 bool Five_digit_broker=true;
 int distance = 10;
 int Countbars=2500;
double b1[];
double b2[];
int init()  {

   SetIndexStyle(0,DRAW_ARROW);
   SetIndexStyle(1,DRAW_ARROW);
   SetIndexArrow(1,Arrowup);
   SetIndexArrow(0,Arrowdown);
   SetIndexBuffer(0,b1);
   SetIndexBuffer(1,b2);
   return(0); 
}
int start() {
   int k,i,j,limit,hhb,llb,limit2,Distancefin;
   int counted_bars = IndicatorCounted();
   if (counted_bars < 0) 
   return (-1);
   if (counted_bars> 0) 
   counted_bars--;
   if (i> limit2) 
   limit2= i;   
   if (limit2 < Countbars - 1)
    limit = Countbars - 1;  
    for (i=limit;i>=0;i--) 
    {
     b1[i]=0;
      b2[i]=0;
}
if (Five_digit_broker==true){
Distancefin=distance*0.1;
}
else{
Distancefin=distance;
}

   for (i=limit;i>=1;i--)   {
     
      hhb = iHighest(0,0,MODE_CLOSE,barsLeftOfCurrent + 0 + barsRightOfCurrent,i - barsRightOfCurrent);
      llb = iLowest(0,0,MODE_CLOSE,barsLeftOfCurrent + 0 + barsRightOfCurrent,i - barsRightOfCurrent);
         if (i==hhb)
         {
         b1[i]=High[hhb]+Distancefin*Point;
         //PlaySound("news.wav"); Alert("["+Symbol()+"] [M"+Period()+"] #PUT");
         }
      if (i==llb)
         {
         b2[i]=Low[llb]-Distancefin*Point;
         //PlaySound("news.wav"); Alert("["+Symbol()+"] [M"+Period()+"] #CALL");
         }
         }
    if (i> limit2) 
   limit2= i;
   return(0);
}