string CheckEntry()

  {
   // create an empty string for the signal
   string signal=""; 
   
   // symbol, period,20 candles, deviation 2, no shift, close price, candle
   double LowerBB=iBands(_Symbol,_Period,20,2,0,PRICE_CLOSE,MODE_LOWER,1);
	double UpperBB=iBands(_Symbol,_Period,20,2,0,PRICE_CLOSE,MODE_UPPER,1);
	
   // calculate the candle before   
   double PrevLowerBB=iBands(_Symbol,_Period,20,2,0,PRICE_CLOSE,MODE_LOWER,2);
   double PrevUpperBB=iBands(_Symbol,_Period,20,2,0,PRICE_CLOSE,MODE_UPPER,2);	
   
	// if price is above the last close
   if (Ask > Close[1]) 
   
	 // if close2 was below lower band
	 if (Close[2]<PrevLowerBB) 
	 
	  // if close1 is above lower band
	  if (Close[1]>LowerBB)    
	  { 
	      signal="buy";
	  }
	  
	// if price is below the last close
	if (Bid < Close[1])
	
	 // if close2 was above upper band
	 if (Close[2]>PrevUpperBB)
	 
	  // if close1 is below upper band
	  if (Close[1]<UpperBB)
	  { 
	      signal="sell";
	  }	
      
  // return the signal to the main module
  return signal;                        
     
 }