function ShowAbstracts() {
 var e = document.getElementsByTagName("span");
 var i;
 for( i = 0; i < e.length; i++ ) {
   if (e[i].className == 'AbstractOn') {
   e[i].style.display = 'block';
   }
  else if (e[i].className == 'AbstractOff') {
   e[i].style.display = 'none';
   }
 }
}

function HideAbstracts() {
 var e = document.getElementsByTagName("span");
 var i;
 for( i = 0; i < e.length; i++ ) {
  if (e[i].className == 'AbstractOff') {
   e[i].style.display = 'block';
   }
  else if (e[i].className == 'AbstractOn') {
   e[i].style.display = 'none';
   }
 }
}

function SlidesShowAbstracts() {
 var e = document.getElementsByTagName("span");
 var i;
 for( i = 0; i < e.length; i++ ) {
   if (e[i].className == 'SlidesAbstractOn') {
   e[i].style.display = 'block';
   }
  else if (e[i].className == 'SlidesAbstractOff') {
   e[i].style.display = 'none';
   }
 }
}

function SlidesHideAbstracts() {
 var e = document.getElementsByTagName("span");
 var i;
 for( i = 0; i < e.length; i++ ) {
  if (e[i].className == 'SlidesAbstractOff') {
   e[i].style.display = 'block';
   }
  else if (e[i].className == 'SlidesAbstractOn') {
   e[i].style.display = 'none';
   }
 }
}