Abstract: An address book is created automatically when a user sends, replies or forwards mail. The email addresses and mobile numbers to which a mail or message has been sent are stored in the address book. This information is presented to the user the next time he tries to compose another email or SMS and types the first character of an email address. The Address Prompter technology of the present invention enables an internet based application to build memory and intelligence into it, by remembering not only the numbers but also the contacts from which the user has received messages.