function horizScroller(opt)
{
   var d = 0;
   opt.delay = opt.delay || 50;
   opt.dist = opt.dist || 2;
   opt.leftEl.onmouseover = function() { d = -opt.dist; scroll(); }
   opt.leftEl.onmouseout = function() { d = 0 }
   opt.rightEl.onmouseover = function() { d = opt.dist; scroll(); }
   opt.rightEl.onmouseout = function() { d = 0 }
   
	function scroll()
   {
	   if (!d) return;
	   var x = opt.contentEl.scrollLeft+d, stop = false, rightBoundary = opt.contentEl.scrollWidth-opt.contentEl.offsetWidth;
	   if (x<0) {
		   addClassName(opt.leftEl, 'disabled');
		   x = 0;
		   stop = true;
	   } else {
		   removeClassName(opt.leftEl, 'disabled');
	   }
	   if (x>=rightBoundary) {
		   addClassName(opt.rightEl, 'disabled');
		   x = rightBoundary;
		   stop = true;
	   } else {
		   removeClassName(opt.rightEl, 'disabled');
	   }
	   opt.contentEl.scrollLeft = x;
	   if (stop) return;
	   window.setTimeout(scroll, opt.delay);
   }
   
   function addClassName(el, className)
   {
	   el.className = el.className.replace(new RegExp(' ?'+className+'|$'), ' '+className);
   }
   
   function removeClassName(el, className)
   {
	   el.className = el.className.replace(new RegExp(' ?'+className+'( |$)'), '$1');
   }
}