function off (name) {
  document[name].src='https://mystamps.com.au/templates/default/images/'+name+'.gif';
}
function on (name) {
  document[name].src='https://mystamps.com.au/templates/default/images/'+name+'_.gif';
}

function imgoff (name) {
  document[name].src='https://mystamps.com.au/templates/default/images/'+name+'.jpg';
}
function imgon (name) {
  document[name].src='https://mystamps.com.au/templates/default/images/'+name+'_.jpg';
}