private void drawGrid(){
		
		//indicate the intervals between vertical lines
		int vertDist = APPLICATION_WIDTH/NDECADES;
		//window fit
		int fit = 60;
		//a buffer for everything
		int buffer =5;
		
		bottomLineY = APPLICATION_HEIGHT-GRAPH_MARGIN_SIZE-fit;
		
		for(int i=0;i<NDECADES;i++){
			decadeArray[i] = START_DECADE + i*10;
			decadeXArray[i] = buffer + i*vertDist;
		}
		
		
		for(int i=0;i<NDECADES;i++){
			GLine vertical = new GLine (decadeXArray[i],0,decadeXArray[i],APPLICATION_HEIGHT-fit);
			add(vertical);
			String decadeString = "" + decadeArray[i];
			GLabel year = new GLabel(decadeString);
			year.setFont("Helvetica-24");
			add(year,i*vertDist+buffer*2,APPLICATION_HEIGHT-fit-buffer);
		}
		
		GLine top = new GLine(0,topLineY,APPLICATION_WIDTH,topLineY);
		GLine bottom =  new GLine(0, bottomLineY,APPLICATION_WIDTH,bottomLineY);
		add(top);
		add(bottom);
	}