function sub0() {
  document.all.submenu0.style.display='block';
  document.all.submenu1.style.display='none';
  document.all.submenu2.style.display='none';
  document.all.submenu3.style.display='none';
}
function sub1() {
  document.all.submenu0.style.display='none';
  document.all.submenu1.style.display='block';
  document.all.submenu2.style.display='none';
  document.all.submenu3.style.display='none';
}
function sub2() {
  document.all.submenu0.style.display='none';
  document.all.submenu1.style.display='none';
  document.all.submenu2.style.display='block';
  document.all.submenu3.style.display='none';
}
function sub3() {
  document.all.submenu0.style.display='none';
  document.all.submenu1.style.display='none';
  document.all.submenu2.style.display='none';
  document.all.submenu3.style.display='block';
}