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：<a href="/News/2021-2/194255">2020-2021学年人教A版数学选修4-4学案 </a>  下一篇：<a href="/News/2021-2/194257">新教材2020-2021学年数学人教B版必修2课时作业 </a> ';
}