window.onload=function(){
	var h1=document.getElementById("J_Tzh");
	var h2=document.getElementById("J_Guang");
	document.getElementById("J_BdSide").style.width='auto';
	
	window.onscroll=function(){
		var h=(document.documentElement.scrollTop||document.body.scrollTop)+(document.documentElement.clientHeight||document.body.clientHeight);
		if(h>=h1.offsetHeight+h2.offsetHeight){
			//h2.style.cssText='position: fixed;top: 0;right: 0;';
			h2.style.position='fixed';
			h2.style.top=(h2-(document.documentElement.clientHeight||document.body.clientHeight))+'px';
			h2.style.right=0;
		}else{
			h2.style.position="static";
		}
	}
	
}

• 用cssText就会出现如下图的问题：

• 用style，就正常。