Up arrow to trigger commenter name

gistfile1.txt

// ==UserScript==
// @name        Up arrow commenter tool
// @namespace   https://gist.github.com/burn123/5674710
// @description Press Up arrow to access the name of the commenter when using the @ symbol
// @include     http://*stackoverflow.com/questions*
// @include     http://*stackoverflow.com/review*
// @include     http://*stackoverflow.com/admin/dashboard*
// @include     http://*stackoverflow.com/tools*
// @include     http://*serverfault.com/questions*
// @include     http://*serverfault.com/review*
// @include     http://*serverfault.com/admin/dashboard*
// @include     http://*serverfault.com/tools*
// @include     http://*superuser.com/questions*
// @include     http://*superuser.com/review*
// @include     http://*superuser.com/admin/dashboard*
// @include     http://*superuser.com/tools*
// @include     http://*stackexchange.com/questions*
// @include     http://*stackexchange.com/review*
// @include     http://*stackexchange.com/admin/dashboard*
// @include     http://*stackexchange.com/tools*
// @include     http://*askubuntu.com/questions*
// @include     http://*askubuntu.com/review*
// @include     http://*askubuntu.com/admin/dashboard*
// @include     http://*askubuntu.com/tools*
// @include     http://*answers.onstartups.com/questions*
// @include     http://*answers.onstartups.com/review*
// @include     http://*answers.onstartups.com/admin/dashboard*
// @include     http://*answers.onstartups.com/tools*
// @include     http://*mathoverflow.net/questions*
// @include     http://*mathoverflow.net/review*
// @include     http://*mathoverflow.net/admin/dashboard*
// @include     http://*mathoverflow.net/tools*
// @include     http://discuss.area51.stackexchange.com/questions/*
// @include     http://discuss.area51.stackexchange.com/review*
// @include     http://discuss.area51.stackexchange.com/admin/dashboard*
// @include     http://discuss.area51.stackexchange.com/tools*
// @include     http://stackapps.com/questions*
// @include     http://stackapps.com/review*
// @include     http://stackapps.com/admin/dashboard*
// @include     http://stackapps.com/tools*
// @version     1
// ==/UserScript==