In xml/common/login.xml, around line 52:

                    <span class='login_text'>
                        <input type='submit' value='Reset My Password' 
onclick='
                            username = prompt("Enter your username");
                            if(!username) return;
                            var req = new 
Request("open-ils.actor:open-ils.actor.user.password.reset.email", 
username);
                            req.callback(
                                function(r) {
                                    status = r.getResultObject();
                                    if(status == 1) {
                                        alert("New password has been 
sent to your email address");
                                    } else {
                                        alert("Unable to reset and email 
your password.  Please see a librarian");
                                    }
                                }
                            );
                            req.send();
                        '/>
                    </span>