function productlist()
{
  var menu= document.getElementById("list").getElementsByTagName("li");
  for(i=0;i<menu.length;i++)
	{
	   menu[i].onclick=function()
       {
		   
		   
		   var aa= document.getElementById("list").getElementsByTagName("li");
		   for(i=0;i<aa.length;i++)
		   {
			   if(aa[i].getElementsByTagName("ul").length!=0)
			   {
				   aa[i].getElementsByTagName("ul")[0].style.display="none";
				   aa[i].style.fontWeight="normal";
			   }
		   }
		   this.getElementsByTagName("ul")[0].style.display="block";
		   this.style.fontWeight="bold";
       }
  }
}