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:2013学年高一鲁科版化学必修1课件(4章汇总) 下一篇:2013学年高一苏教版化学必修2学案(全册) '; }