function setVisible(obj)
{
	obj = document.getElementById(obj);
	obj.style.visibility = (obj.style.visibility == 'visible') ? 'hidden' : 'visible';
}
function multiImage() {
  if (document.sharedbook.themechoice[0].checked) {
	  document.conditionalimage.src="images/blue_book.gif";
    }
  else if (document.sharedbook.themechoice[1].checked) {
	  document.conditionalimage.src="images/brown_book.gif";
    }
  else if (document.sharedbook.themechoice[2]. checked) {
	  document.conditionalimage.src="images/purple_book.gif";
    }
  else {
	  document.conditionalimage.src="images/blue_book.gif";
    }
	}