function Cargar_Imagen_PopUp(img, ancho, alto){
  derecha=(screen.width-ancho)/2;
  arriba=(screen.height-alto)/2;
  parametros="toolbar=no,scrollbars=no,location=0,statusbar=no,menubar=no,resizable=no,width="+ancho+",height="+alto+",left="+derecha+",top="+arriba+"";
  fin=window.open(img,"",parametros);
}

function popUp(URL,ancho,alto) {
	derecha=(screen.width-ancho)/2;
	arriba=(screen.height-alto)/2;
	parametros="toolbar=no,scrollbars=no,location=0,statusbar=no,menubar=no,resizable=no,width="+ancho+",height="+alto+",left="+derecha+",top="+arriba+"";
	fin=window.open(URL,"",parametros);	
}