function abre(menu) {
     document.getElementById(menu).style.display="block";
     document.getElementById(menu).style.overflow="visible";
     }
function cierra(menu) {
     document.getElementById(menu).style.display="none";
     document.getElementById(menu).style.overflow="hidden";
     }

function ampliarinf(enl) {
    var ventana=window.open (enl,'ventana','height=640,width=600,top=65,left=200');
    ancho=600;
    alto=640;
    ventana.moveTo((screen.width-ancho)/2,(screen.height-alto)/2);
    ventana.focus();
  }

function switch_id(selectobj) 
{ 

    if (selectobj == '') 
    { 
        return; 
    } 

    ampliarinf(selectobj);
}