function showhide(divid, i) {

 if (document.getElementById(divid).style.visibility=='visible')
 {
  document.getElementById(divid).style.visibility='hidden';
  document.getElementById(divid).style.display='none';
  document.images[i].src="gfx/gfx/arrow_down_blue.gif";
 }
 else
 {
  document.getElementById(divid).style.visibility='visible';
  document.getElementById(divid).style.display='block';
  document.images[i].src="gfx/gfx/arrow_up_gray.gif";
 } 
                          }