@namespace url(http://www.w3.org/1999/xhtml);

@-moz-document domain("mail.comcast.net") {

#comcast-adsrvc, #skin_adsrvc, #skin_container_sidebar_ad, #comcast-skyscrapperad, #comcast-adinfo, #skin_td_tree_bottom_ad, #skin_container_top_ad, #skin_tr_top_ad, #skin_sidebar_ad_outer, #skin_td_sidebar_ad {
display:none !important;
}

}