var refer=true;
function combo() {
if (refer) {
  document.all.contents.style.display='none';
  refer=false;
}
else {
  document.all.contents.style.display='block';
  refer=true;
}
}

function combo1() {
if (refer) {
  document.all.contents1.style.display='none';
  refer=false;
}
else {
  document.all.contents1.style.display='block';
  refer=true;
}
}

function combo2() {
if (refer) {
  document.all.contents2.style.display='none';
  refer=false;
}
else {
  document.all.contents2.style.display='block';
  refer=true;
}
}

function combo3() {
if (refer) {
  document.all.contents3.style.display='none';
  refer=false;
}
else {
  document.all.contents3.style.display='block';
  refer=true;
}
}

function combo4() {
if (refer) {
  document.all.contents4.style.display='none';
  refer=false;
}
else {
  document.all.contents4.style.display='block';
  refer=true;
}
}



function combo5() {
if (refer) {
  document.all.contents5.style.display='none';
  refer=false;
}
else {
  document.all.contents5.style.display='block';
  refer=true;
}
}