function openmenu(mp) {

 closeall();

 i = document.getElementById(mp);
 i.style.display = "block";
 i.style.visibility = "visible";
}

function closemenu() {
 closeall();

 i = document.getElementById(mp);
 i.style.display = "none";
 i.style.visibility = "hidden";
}

function closeall() {
 for(n=1;n<5;n++){
  i = document.getElementById('m_0'+n);
  i.style.display = "none";
  i.style.visibility = "hidden";
 }
}