void  ChartRedraw(
   long  chart_id=0      // Chart ID
   );

#define   WIDTH      50    // rectangle width in bars

//+------------------------------------------------------------------+
//| Script program start function                                    |
//+------------------------------------------------------------------+
void OnStart()
  {
//--- get the current chart ID and set the graphical object name
   long   chart_id = ChartID();
   string obj_name = MQLInfoString(MQL_PROGRAM_NAME)+"_RectLabel";

//--- get two rectangle time coordinates
   datetime time1  = iTime(_Symbol, _Period, WIDTH);
   datetime time2  = iTime(_Symbol, _Period, 0);
   if(time1==0 || time2==0)
     {
      Print("Error getting time ", GetLastError());
      return;
     }

//--- get the maximum and minimum prices in the range of the rectangle width
   double price1 = HighestHigh(_Symbol, _Period, 0, WIDTH);
   double price2 = LowestLow(_Symbol, _Period, 0, WIDTH);
   if(price1==EMPTY_VALUE || price2==EMPTY_VALUE)
      return;

//--- create a rectangle object
   Print("Create a wheat-colored rectangle");
   if(!ObjectCreate(chart_id, obj_name, OBJ_RECTANGLE, 0, time1, price1, time2, price2))
     {
      Print("ObjectCreate() failed. Error ", GetLastError());
      return;
     }

//--- fill the rectangle with the original color
   ObjectSetInteger(chart_id, obj_name, OBJPROP_FILL, true);
   ObjectSetInteger(chart_id, obj_name, OBJPROP_BACK, true);
   ObjectSetInteger(chart_id, obj_name, OBJPROP_COLOR, clrWheat);
   ChartRedraw();

//--- wait a second, fill the rectangle with the DodgerBlue color and update the chart
   Sleep(1000);
   Print("Change color to DodgerBlue");
   ObjectSetInteger(chart_id, obj_name, OBJPROP_COLOR, clrDodgerBlue);
   ChartRedraw();

//--- wait a second, fill the rectangle with the LimeGreen color and update the chart
   Sleep(1000);
   Print("Change color to LimeGreen");
   ObjectSetInteger(chart_id, obj_name, OBJPROP_COLOR, clrLimeGreen);
   ChartRedraw();

//--- wait a second, fill the rectangle with the OrangeRed color and update the chart
   Sleep(1000);
   Print("Change color to OrangeRed");
   ObjectSetInteger(chart_id, obj_name, OBJPROP_COLOR, clrOrangeRed);
   ChartRedraw();

//--- wait a second, fill the rectangle with the Wheat color and update the chart
   Sleep(1000);
   Print("Reset color to original");
   ObjectSetInteger(chart_id, obj_name, OBJPROP_COLOR, clrWheat);
   ChartRedraw();

//--- after three seconds, remove the object from the chart
   Sleep(3000);
   Print("Delete the rectangle");
   ObjectDelete(chart_id, obj_name);
  }
//+------------------------------------------------------------------+
//| Return the maximum High in the specified range of bars           |
//+------------------------------------------------------------------+
double HighestHigh(const string symbol, const ENUM_TIMEFRAMES timeframe, const uint start, const uint count)
  {
   ResetLastError();
   int index=iHighest(symbol, timeframe, MODE_HIGH, count, start);
   if(index==-1)
     {
      PrintFormat("%s: iHighest() failed. Error %d",__FUNCTION__, GetLastError());
      return(EMPTY_VALUE);
     }
   GetLastError();
   double price=iHigh(symbol, timeframe, index);
   if(price==0)
     {
      PrintFormat("%s: iHigh() failed. Error %d",__FUNCTION__, GetLastError());
      return(EMPTY_VALUE);
     }
   return(price);
  }
//+------------------------------------------------------------------+
//| Return the minimum Low in the specified range of bars            |
//+------------------------------------------------------------------+
double LowestLow(const string symbol, const ENUM_TIMEFRAMES timeframe, const uint start, const uint count)
  {
   ResetLastError();
   int index=iLowest(symbol, timeframe, MODE_LOW, count, start);
   if(index==-1)
     {
      PrintFormat("%s: iLowest() failed. Error %d",__FUNCTION__, GetLastError());
      return(EMPTY_VALUE);
     }
   GetLastError();
   double price=iLow(symbol, timeframe, index);
   if(price==0)
     {
      PrintFormat("%s: iLow() failed. Error %d",__FUNCTION__, GetLastError());
      return(EMPTY_VALUE);
     }
   return(price);
  }