What about on-line purchases?
In the case of electronic web-based contracts, acceptance must be communicated, that is the instantaneous communications rule applies. 
The postal rule - acceptance becomes effective as soon as despatch is normally not applicable to web-based electronic contracts, however it is applicable to e-mail based contracts since they operate essentially in the same way as traditional correspondence. The postal rule is a customary rule and therefore can be amended by contractual terms.
Instantaneous communications rule - acceptance must be confirmed by the other side. E-mail is notoriously difficult to define under the rules of contractual communication. It can be argued either way, but it is submitted that e-mail contracts are substantively different from internet based contracts. In any e-contract, it should be made clear how the offer is to be accepted, in order to avoid any ambiguity and the attendant risk of unenforceability.
The biggest concern in on-line contracts and the communication rules concerns the price. What about the webpage which advertises a television for £2.99 when in actual fact the price shou英语论文网 【http://www.51lunwen.org】ld be £299. Is the retailer bound by the webpage mistake? This issue has never really been tested in the courts. In the Argos case, Argos could probably get out of the contract by stating that it had not send a confirming e-mail, stating that delivery would definitely occur. In the Kodak case, Kodak settled out of court and agreed to honour the camera contracts at £100 rather than go to court and argue the real price should have been £300 since Kodak had sent a confirming e-mail to each prospective customer.

Intelligibility of the Communication
The intelligibility of a communication may be a question where the communication is garbled, or needs to be decoded in some way, or the parties expect communications to be confirmed as understood before being acted upon. There may be issues of miscommunication concerning where a communication is sent to, and even if sent or received within or outwith normal business hours. Most traditional forms of communication do not result in a garbled message – the spoken word, the written word, the telex, however modern forms of communication may result in digitised data becoming mixed-up/altered/deleted.

There are clearly then important legal and technological issues concerning the communication of offers and acceptances for e-commerce. E-commerce presents special issues of how instantaneous any communication is, for example clicking on a button on a website. There may be technological issues of how to estab 本文来自：英语论文网 【http://www.51lunwen.org】