if( document.domain.match( new RegExp("(.yahoo.co.jp)$","i") ) ){
  document.write("<img width=1 height=1 style=\"position:absolute;\" alt=\"\" src=\"https://b13.yahoo.co.jp/b?P=0iC_bTE4My64ddV_YF5k6wAAMTk4LmBeblcADkC2&T=143ba9a6r%2fX%3d1616801367%2fE%3d2077296265%2fR%3djp_toppage%2fK%3d5%2fV%3d8.1%2fW%3d0R%2fY%3djp%2fF%3d348590363%2fQ%3d-1%2fS%3d1%2fJ%3dc61b513b&U=125nsk20d%2fN%3dMzk4MDE4My4-%2fC%3d-2%2fD%3dZ%2fB%3d-2&Q=1\">");
} else {
  console.log("error: domain param and document.domain do not match");
}