// JavaScript Document
function showImage(elem) {
	if(!document.getElementById) {
		return false;
	} else {
		var bigPic = elem.getAttribute('href');
      var newCaption = elem.firstChild.getAttribute('alt');
      var newPic = document.getElementById('mainpic').firstChild;
      newPic.setAttribute('src',bigPic);
      var theCaption = document.getElementById('picCaption');
      theCaption.firstChild.nodeValue = newCaption;
      newPic.setAttribute('alt',newCaption);
	}
}