Loại bỏ nút menu của firefox (app button)

Thêm code sau vào user css (cách sử dụng css xem ở bài này http://kukungkung.wordpress.com/2012/01/11/lam-firefox-trong-su%e1%bb%91t-khong-c%e1%ba%a7n-cai-add-on/)
#appmenu-button {
background: none !important;
border: none !important;
box-shadow: none !important;
margin: 0 0 2px 0 !important;
}

#main-window[sizemode="maximized"][tabsontop="true"] #appmenu-button {
margin: -7px 0 2px 0 !important;
padding: 0 9px 0 0 !important;
min-width: 0 !important;
}
#appmenu-button:hover {
background-color: rgba(255,255,255,.4) !important;
border: 1px solid rgba(0,0,0,.6) !important;
border-top: none !important;
}
#appmenu-button .button-text, #appmenu-button > .button-box > .button-menu-dropmarker {
visibility: collapse !important;
}