function showmenu(id) {
   document.getElementById(id).style.visibility = 'visible';
}
function hidemenu(id) {
   document.getElementById(id).style.visibility = 'hidden';
}

function show(id) {
   document.getElementById(id).style.visibility = 'visible';
}
function hide(id) {
   document.getElementById(id).style.visibility = 'hidden';
}