private void changeImage(Event e , String option){
		if(e instanceof MouseEvent){
			//get the source of event
			ImageView ev = (ImageView)e.getSource() ;
			String loc = null ;
			
			if(ev.getId().equals("departmentImageView")){
				loc = "/images/school7" + option  + ".png" ;
			}else if(ev.getId().equals("teacherImageView")){
				loc = "/images/teach"  + option  +  ".png" ;
			}else if(ev.getId().equals("roomImageView")){
				loc = "/images/classroom1"  + option  +  ".png" ;
			}else if(ev.getId().equals("courseImageView")){
				loc = "/images/university2"  + option  +  ".png" ;
			}else if(ev.getId().equals("yearImageView")){
				loc = "/images/amount"  + option  +  ".png" ;
			}else if(ev.getId().equals("sectionImageView")){
				loc = "/images/homework"  + option  +  ".png" ;
			}else if(ev.getId().equals("subjectImageView")){
				loc = "/images/open3" + option + ".png" ;
			}
		
			//set the image base on LOC
			ev.setImage(new Image(getClass().getResourceAsStream(loc)));
		}
	}