function chkdiv(divid){ var chkid=document.getElementById(divid); if(chkid != null){return true; } else {return false; } } if (chkdiv('fy')){ document.getElementById('fy').innerHTML='上一篇:2019高考数学(理)优编增分二轮(全国通用版)课件+文档 下一篇:2019高考数学(京、津)专用(理)优编增分练 '; }