public void setHistoryLocation(int i) {
		this.history_location = i;
		
		if (this.history_location <= 0) {
			this.prevButton.setEnabled(false);
		} else {
			this.prevButton.setEnabled(true);
		}
		//System.out.println(this.history_location + ":" + history.getSize());
		if (this.history_location >= history.getSize() - 1) {
			this.nextButton.setEnabled(false);
		} else {
			this.nextButton.setEnabled(true);
		}
	}