// JavaScript Document
Event.observe(window,'load',function(){
	modifica_boton();
});
function modifica_boton(){
	var botones = document.getElementsByTagName('button');
	for(var boton in botones){
		Event.observe(botones[boton], 'mouseover',modifica_boton_over.bindAsEventListener(botones[boton]));
		Event.observe(botones[boton], 'mouseout',modifica_boton_out.bindAsEventListener(botones[boton]));
	}
}
function modifica_boton_over(e){
			this.addClassName('bt_over');
}
function modifica_boton_out(e){
			this.removeClassName('bt_over');
}