var interval=0.12;
var lastElement="currentsemester";
var inProgress="false";
function OnAppearFinish(obj){
  inProgress="false";
}
function SwitchEffect(element){
  if (inProgress=="true") {return;}
  if (lastElement!=element) {
    inProgress="true";
    new Effect.Fade(lastElement,{duration:interval});
    new Effect.Appear(element,{duration:interval, delay:interval+0.03, afterFinish:OnAppearFinish});
    lastElement=element;
  }
}