function prepareGallery() {
  if (!document.getElementsByTagName) return false;
  if (!document.getElementById) return false;
  if (!document.getElementById("fotosalunos")) return false;
  var gallery = document.getElementById("fotosalunos");
  var links = gallery.getElementsByTagName("a");
  for ( var i=0; i < links.length; i++) {
    links[i].onclick = function() {
      return showPic(this);
    }
  }
}
window.onload=prepareGallery;

function showPic(whichpic) {
  if (!document.getElementById) return true;
  area = document.getElementById('imgalunos')
  area.src = whichpic.href;
  area.style.display="block";
  return false;
}

function hide(elemento) {
  if (!document.getElementById) return true;
  elemento.style.display="none";
  return false
}