function expand(id)
{
 var obj=document.getElementById(id);
 if (obj.style.display=='block') {obj.style.display='none';return;}
 if (obj.style.display=='none')  {obj.style.display='block';return;}
}
function expand_and_change_sign(id, idsign)
{
 var obj =document.getElementById(id);
 var sign=document.getElementById(idsign);
 if (obj.style.display=='block') 
		{  
			obj.style.display='none';
			sign.innerHTML="+";
			return;
		}
 if (obj.style.display=='none')  
		{
			obj.style.display='block';
			sign.innerHTML="-";
			return;
		 }

}