function otvori_odgovor(n)
{			
	a1.style.display = "none";
	a2.style.display = "none";	
	a3.style.display = "none";	
	a4.style.display = "none";	
	a5.style.display = "none";	
	a6.style.display = "none";	
	a7.style.display = "none";	
	a8.style.display = "none";	
	a9.style.display = "none";	
	a10.style.display = "none";	
	a11.style.display = "none";	
	a12.style.display = "none";	
	a13.style.display = "none";	
	a14.style.display = "none";	
	a15.style.display = "none";	
	a16.style.display = "none";	
	a17.style.display = "none";	
	a18.style.display = "none";	
	a19.style.display = "none";	
	a20.style.display = "none";	
		
	
		o = document.all["a"+String(n)];
	if (typeof(o) == "object")
	{
		if (o.style.display == "none")
			o.style.display = "";
		else
			o.style.display = "none";
	}
}