function buttonClick(obj){
  if (obj.src)
    obj.src = obj.src.replace(/.gif/, '_Inset.gif'); 
  if (obj.currentStyle)
    var style = obj.currentStyle;
  else if (document.defaultView && document.defaultView.getComputedStyle)
    var style = document.defaultView.getComputedStyle(obj,'');
  if (!style) return false;
  obj.style.backgroundImage = style.backgroundImage.replace(/.gif/, '_Inset.gif'); 
}

function buttonReset(obj){
  if (obj.src)
    obj.src = obj.src.replace(/_Inset.gif/, '.gif')
  if (obj.currentStyle) 
    var style = obj.currentStyle;
  else if (document.defaultView && document.defaultView.getComputedStyle)
    var style = document.defaultView.getComputedStyle(obj,'');
  if (!style) return false;
  obj.style.backgroundImage = style.backgroundImage.replace(/_Inset.gif/, '.gif')
  obj.style.backgroundImage = style.backgroundImage.replace(/_Hover.gif/, '.gif')
}