20 The authors of the fourth edition of Meagher, Gummow & Lehane's Equity Doctrines & Remedies say at [21-410] that the importance of an undertaking is immense, as in the absence of an undertaking a defendant who is ultimately victorious at the final hearing has no recourse to recover the damages he may have incurred from complying with an interlocutory injunction: Chisholm v Rieff (1953) 2 FLR 211; Bond Brewing Holdings Ltd v National Australia Bank Ltd (No 2) [1991] VicRp 31; [1991] 1 VR 386; (1991) 1 ACSR 445. In Air Express Ltd v Ansett Transport Industries (Operations) Pty Ltd [1981] HCA 75; (1981) 146 CLR 249 Gibbs J said that the object of requiring a plaintiff who seeks an interlocutory injunction to enter into an undertaking as to damages is to attempt to ensure that a defendant will receive compensation for any loss which he suffers by reason of the grant of the injunction if it appears in the event that the plaintiff was not entitled to obtain it (311). His Honour said that the insistence upon the giving of an undertaking 'is a very important, if not an essential, means of preventing injustice from being done by the court' when it makes an order at an interlocutory stage before the rights of the parties have been finally determined. Gibbs J said that the appellant could not obtain damages for any loss which resulted to it by reason of the injunction because at the time it was not a defendant and was not entitled to the benefit of the undertaking (314). Stephen J said that a plaintiff who sues for an injunction and obtains interlocutory relief, giving an undertaking to the court as the price of that relief, commits no wrongful act when, at the trial, he fails to obtain any perpetual injunction but, if as a result of the grant of interlocutory relief, the defendant has been harmed there will have been an injustice and, an undertaking having been given, the court 'will thereby have been armed with jurisdiction, otherwise lacking' to right that injustice and compensate the defendant for the harm done to him (319 - 320).