public void actionPerformed(ActionEvent event){
		
		if (event.getActionCommand().equals(loadStr)){
			// create BufferedReader
	        try {
	            book = PDDocument.load(new File(fileName));
	            bookGrain = book.getNumberOfPages();
	            but_run.setEnabled(true);
	        } catch (IOException e) { //
	        	// if file not found don't care but don't let us run. 
	        	System.out.printf("Can't find file: %s.\n", fileName);
	        };
	        
	    //These handle the radio  button (for now).
		} else if (event.getActionCommand().equals(sentimentStr)){
			genType = sentimentStr;
			label.setVisible(false);
			check_block.setEnabled(true);
		} else if (event.getActionCommand().equals(stemStr)){
			genType = stemStr;			
			label.setVisible(true);
			check_block.setEnabled(false);
		//Then, if we trigger the run event, we should run!
		} else if (event.getActionCommand().equals(runStr)){
			
			negCount = 0;
			posCount = 0;
			if (genType.equals(stemStr)){
				paintPage(paint, pageStart, pageEnd);
			}
			else {
				float[] maxs = analyzeBook();
				paintBook(paint, maxs[0], maxs[1]);
			};
			
//			try{ //And, because of IO, we have to try to close the pdf. 
//				book.close();
//			} catch (IOException e){};
		}
 
	}