function imgswitch(e, act){
	var imag = e.src;
	var deb = imag.indexOf('_off.gif');
	var deb2 = imag.indexOf('_on.gif');
	if(deb != -1){
		racine = imag.substring(0,deb);
	}
	if(deb2 != -1){
		racine = imag.substring(0,deb2);
	}
	//alert(racine+'|'+deb+'-'+deb2);
	var nouv = racine+'_'+act+'.gif';
	e.src = nouv;
}

Event.observe(window, 'load', function() {
  var imgs=$$('img.to_hover');
  for(var i=0;i<imgs.length;i++){
  	Event.observe(imgs[i],'mouseover',function(event){
  		imgswitch(Event.element(event),'on');
 		});
  	Event.observe(imgs[i],'mouseout',function(event){
  		imgswitch(Event.element(event),'off');
 		});
  }
  var chps=$$('input.to_hover');
  for(var i=0;i<chps.length;i++){
  	Event.observe(chps[i],'mouseover',function(event){
  		imgswitch(Event.element(event),'on');
 		});
  	Event.observe(chps[i],'mouseout',function(event){
  		imgswitch(Event.element(event),'off');
 		});
  }
});