function swap_image_on ( e ) {
 if ( e.target ) {
  target_node = e.target.id;
 } else {
  target_node = e.srcElement.id;
 }

 document.getElementById(target_node).src = '../common/images/' + target_node + '_on.gif';
}


function swap_image_off ( e ) {
 if ( e.target ) {
  target_node = e.target.id;
 } else {
  target_node = e.srcElement.id;
 }

 document.getElementById(target_node).src = '../common/images/' + target_node + '_off.gif';
}


function pulldownmenu ( e ) {
 if ( e.target ) {
  target_node = e.target.id;
 } else {
  target_node = e.srcElement.id;
 }

 location.href = document.getElementById(target_node).value;
}