function enlarge_image(image) {
  if (image.className == 'small') {
    //    alert('increasing' + image.className);
    var height = image.height;
    var width = image.width;
    image.height = 5*height;
    image.width = 5* width;
    image.className = 'large';
  }
  else {
    // alert('increasing' + image.className);
    var height = image.height;
    var width = image.width;
    image.height = 0.2*height;
    image.width = 0.2* width;
    image.className = 'small';
  }
}

function showPic(whichpic) {
  var source = whichpic.getAttribute("src");
  var placeholder = document.getElementById("placeholder");
  placeholder.setAttribute("src",source);
}