function  clear()
{ 
index_text1.style.display="none";
kuai1.style.background="url(images/kuai2.gif)";
index_text2.style.display="none";
kuai2.style.background="url(images/kuai2.gif)";
index_text3.style.display="none";
kuai3.style.background="url(images/kuai2.gif)";

}
function doo(ul,img)
{   
   var ulobj=document.getElementById(ul);
   var imgobj=document.getElementById(img);

   //alert(imgobj.src+"  "+ulobj.style.display);
   clear();
   if(ulobj.style.display="none")
     {  
       imgobj.style.background="url(images/kuai1.gif)";
	  ulobj.style.display="block";
   }

}