var rep = [];
var cur = 0;
var INTERVAL = 3800;
var SPEED = 50;
var STEP = 2;
var op = 100;
var fader = null;
var swapper = null;
var next;

var acontinue = true;
window.alert = function ( str ) {
   acontinue = (acontinue && confirm ( str ) );
}

function addToRepository ( img ) {
   rep.push(img);
}

function startFader () {
   if ( rep.length > 0 ) {
      rep[cur].style.visibility='visible';
      if ( rep.length > 1 ) {
         swapper = setTimeout ( 'swapImg()', INTERVAL );
      }
   }
}

function swapImg () {
   next = cur +1;
   if ( !(next in rep) ) {
      next = 0;
   }
   rep[cur].style.zIndex = 2;
   rep[next].style.zIndex = 1;
   rep[next].style.filter='alpha(opacity=100)';
   rep[next].style.opacity=1;
   rep[next].style.MozOpacity=1;
   rep[next].style.visibility='visible';
   
   fader = setInterval ( 'fadeOut()', SPEED );
}

function fadeOut () {
   rep[cur].style.filter='alpha(opacity=' + op + ')';
   rep[cur].style.opacity= (op/100);
   rep[cur].style.MozOpacity= (op/100);
   op -= STEP;
   if ( op == 0 ) {
      rep[cur].style.visibility='hidden';
      clearInterval ( fader );
      fader = null;
      cur = next;
      op = 100;
      swapper = setTimeout ( 'swapImg()', INTERVAL );
   }
}