public String execute() {
		String returnVal = SUCCESS;

		if (getSubmit() != null && SUBMIT.equals(getSubmit())) {
			LibraryManagementFacade facade = new LibraryManagementFacade();
			try {
				Calendar calendar = Calendar.getInstance();
				if ("issue".equals(getAction())) {
					Date issueDate = calendar.getTime();
					getIssueBookVO().setIssueDate(issueDate);
					facade.issueBook(getIssueBookVO());
					addActionMessage("Book " + issueBookVO.getBookID()
							+ " is issued to " + issueBookVO.getStudentID());
				} else if ("receive".equals(getAction())) {
					Date receiveDate = calendar.getTime();
					getIssueBookVO().setReceiveDate(receiveDate);
					facade.receiveBook(getIssueBookVO());
					addActionMessage("Book " + issueBookVO.getBookID()
							+ " is received by " + issueBookVO.getStudentID());
				}
			} catch (LibraryManagementException e) {
				addActionError(e.getExceptionCategory().getMessage());
				returnVal = ERROR;
			}
		} else {
			returnVal = "issuebook"; // when comes first time
		}
		return returnVal;
	}