@Override 
	public boolean equals(Object obj)//test each conditions work well
	{
		//boolean equals = false; 
		if(this.getClass()==obj.getClass())//determine whether the type is same or not.
		{
			if(this.seat.length ==((SeatChart)obj).seat.length )  
			{// because after determining, we can use cast here(we know it is similer data type)
				for(int index =0; index < seat.length; index++)
				{
					if(seat[index] != ((SeatChart)obj).seat[index])
					{
						System.out.printf("No. %d seat does not much.", index);
						return false;
					}
				}
				System.out.println("both are same seat chart");
				return true;
			}
		}
		
		return false;
		
		
	}