var loadingDiv;
var contentDiv;
var transitionState = 0;
 
window.onload = function () {
  loadingDiv = new Fx.Slide('loadingDiv', {onComplete: nextTransition});
  loadingDiv.hide();
  contentDiv = new Fx.Slide('contentDiv', {onComplete: nextTransition});
}
 
function swapThem() {
  if(transitionState == 0) {
    transitionState = 1;
    contentDiv.slideOut();
  }
  else {
    transitionState = 2;
    loadingDiv.slideOut();
  }
}
 
function nextTransition() {
  if(transitionState == 1) {
    transitionState = 3;
    loadingDiv.slideIn();
  }
  else if (transitionState == 2) {
    transitionState = 4;
    contentDiv.slideIn();
  }
  else if (transitionState == 4) {
    transitionState = 0;
  }
}