function addImage(pid, src)
{
  if (document.getElementById(pid))
  {
    var parent = document.getElementById(pid);
    var img = document.createElement("img");
    img.setAttribute("src", src);
    img.setAttribute("border", "0");
    parent.appendChild(img);
  }
}

function clearElement(pid)
{
  var parent;
  var childs;
  var removed;

  if (document.getElementById(pid))
  {
    parent = document.getElementById(pid);
    if (parent.hasChildNodes())
    {
      childs = parent.childNodes;
      var x = childs.length;
      for (i=0; i<x; i++)
      {
        removed = parent.removeChild(childs[0]);
      }
    }
  }
}

function showPic(src)
{
  clearElement('bigImage');
  addImage('bigImage', src);
}