function ampliar_referencia(URL){ 
		 nueva_ventana =window.open(URL,"referencia","top=0,left=0,width=620,height=550,scrollbars=NO")					 
} 
function ampliar_promocion(URL){ 
		 nueva_ventana =window.open(URL,"promocion","top=0,left=0,width=740,height=550,scrollbars=NO")					 
}