/******************************************************
**
**	File:		carousels.js
**
**	Author:		Gordon Irving
**			Mediasurface (Scotland) Ltd
**
**	Version:	1.0
**
**	Date:		12th September 2007
**
*******************************************************/

var carouselCollection = new Array();
var carouselDelay = 4000; // milliseconds
var carouselsTriggered = false;

function carouselsShift() {
  for (var carouselName in carouselCollection) {
    eval('var aCarousel  = window.'+carouselName+';');
    if ( aCarousel ) {
      var carouselSize     = aCarousel.length;
      var carouselPosition = carouselCollection[carouselName];
    
      for (var pos=0; pos<carouselSize; pos++) {
        var hideableObjId = aCarousel[pos];
        var hideableObj   = document.getElementById(hideableObjId);
        if (hideableObj) { hideableObj.style.display = (pos==carouselPosition) ? "block" : "none"; }
      }
    
      if ( ++carouselPosition >= carouselSize ) { carouselPosition = 0; }
      carouselCollection[carouselName] = carouselPosition;
    }
    
    setTimeout("void(0)", 500);
    
  }

  setTimeout("carouselsShift()", carouselDelay);
}

function carouselTrigger() {
  if ( ! carouselsTriggered ) {
    setTimeout("carouselsShift()", 400);
    carouselsTriggered = true;
  }
}