public void read(){
		try {
			FileInputStream fis1;
			fis1 = new FileInputStream("Datas/AccountPO.out");
			FileInputStream fis2  = new FileInputStream("Datas/CollectionOrPaymentPO.out") ;
			FileInputStream fis3 = new FileInputStream("Datas/CashPO.out");
			
			if(fis1.available()>0 ){
			ObjectInputStream oin1 ;
			oin1 = new ObjectInputStream(fis1);
			accounts=(ArrayList<AccountPO>)oin1.readObject();
			}
			
			if(fis2.available()>0){
				ObjectInputStream oin2 = new ObjectInputStream(fis2) ;
				cpReceipts = (ArrayList<CollectionOrPaymentPO>)oin2.readObject() ;
			}
			if(fis3.available()>0){
				ObjectInputStream oin3 = new ObjectInputStream(fis3) ;
	    		cashReceipts = (ArrayList<CashPO>)oin3.readObject() ;
			}
			
			} catch (FileNotFoundException e2) {
				// TODO Auto-generated catch block
				e2.printStackTrace();
			}          
			catch (IOException e1) {
				// TODO Auto-generated catch block
				e1.printStackTrace();
			} 
		     catch (ClassNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}