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/2012-10/54936">准确描述化学实验现象 </a>  下一篇：<a href="/News/2012-10/54938">水果保鲜剂的制备 </a> ';
}