var active_answer = "";
var active_img = ""
function show_answer(eid) {
	img = eid+'_arrow';
  if (active_img !="") 
	{
		document.getElementById(active_img).src = "/images/arrow.jpg";
  }
	document.getElementById(img).src = "/images/down_arrow.jpg";
  active_answer = eid;
	active_img = img;
}