function toggleshow(tag){
  img = tag + "_img";
  tpc = tag + "_tpc";
  p = document.getElementById(tpc);
  i = document.getElementById(img);
  d = p.style.display;
		if (d == "none"){
			p.style.display = "block";
			i.src = "images/logos/_minus.gif"
		}
		if (d == "block") {
			p.style.display = "none";
			i.src = "images/logos/_plus.gif"
		}
}