Sending the user their forgotten password via emal??

Hi all I would like to offer my users the chance to have their username and password sent to them via the email address stored. As i see it i have two issues (1) how do i do the verify email thing where the script send a click here to confirm email address on registration application (2) how do i then send their details (username / password) to the confirmed stored email address. I have looked around but cqnt find the answer..... 5 books on the shelf give no clue either.... Any help is most apreciated Thanks in Advance Dave C