var timeout;
var delay = 10;

function recScroll(elementId, direction, speed) {
  	clearTimeout(timeout);
  	var intElemScrollTop = window.document.getElementById(elementId).scrollTop;
  	if (direction == 'down') {
    	window.document.getElementById(elementId).scrollTop = intElemScrollTop + speed;
  	} else {
    	window.document.getElementById(elementId).scrollTop = intElemScrollTop - speed;
  	}
  	if (intElemScrollTop != window.document.getElementById(elementId).scrollTop ) {
    	timeout=setTimeout("recScroll('"+elementId+"', '"+direction+"', "+speed+");",delay);
  	} else {
    	recScrollLimit(elementId,direction);
  	}
}
function recScrollStop() {
  	clearTimeout(timeout);
}
function recScrollLimit(elementId, direction) {
  //alert("You can't keep scrolling "+elementId+" "+direction+".");
}

function recScrollBy(elementId, direction, pixels, speed) {
  	clearTimeout(timeout);
  	if (pixels > 0) {
    	var intElemScrollTop = window.document.getElementById(elementId).scrollTop;
    	if (direction == 'down') {
      		window.document.getElementById(elementId).scrollTop = intElemScrollTop + speed;
    	} else {
      		window.document.getElementById(elementId).scrollTop = intElemScrollTop - speed;
    	}
    	pixels = pixels - speed;
    	timeout = setTimeout("recScrollBy('" + elementId + "', '" + direction + "', " + pixels + ", " + speed + ");",delay);
  	}
}

function scrollWheel(event) {
	reposition_on_scroll_div_cover() ;
  	var delta = 0;
  	var pixelsPerEvent = 40;
  	var elementId = 'thumbnails';

  	/* Delta is a multiple of 120 (except for Mozilla where it is a multiple of 3) */
  	/* In Opera and Mozilla the delta is negative compared to IE. */
  	if (!event) /* Get the event for IE. */
    	event = window.event;
  	if (event.wheelDelta) { /* IE/Opera. */
    	delta = event.wheelDelta/120;
    	if (window.opera)
      		delta = -delta;
  	} else if (event.detail) { /* Mozilla */
    	/* I'm not going to divide by 3 since Mozilla's scrolling is so slow. */
     	delta = -event.detail;
 	}

  	/* Act if delta != 0 */
  	if (delta) {
    	if (delta < 0) {
      		direction = 'down';
      		delta = -delta;
    	} else {
      		direction = 'up';
    	}
    	pixels = pixelsPerEvent * delta;
    	speed = delta * 5;
    	//alert("Scrolling "+elementId+" "+direction+" by "+pixels); /* for debugging */
    	recScrollBy(elementId,direction,delta,speed);
  	}
}

/* Initialization code. */
/* Mozilla browsers use DOMMouseScroll which listens for scrolling _anywhere_ on the window */
if (window.addEventListener)
  	window.addEventListener('DOMMouseScroll', scrollWheel, false);