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/2010-3/19292">数学新人教版复习教案：等差数列 </a>  下一篇：<a href="/News/2010-3/19294">《机械振动的传播》教学资料汇总 </a> ';
}