var adID;
function imageRotator(Direction)
  {
  // all the homepage ad data
  var homepageImgs = new Array();
  homepageImgs[0] = ("bus-resource.jpg");
  homepageImgs[1] = ("morningstar.jpg");
  homepageImgs[2] = ("refUSA.jpg");
  homepageImgs[3] = ("street.jpg");
  var imgItems = homepageImgs.length;
  var aIndex = 0;
  var flag = 0;
  var content = "";

  if (Direction == "start")
    {
    var randomNumber = Math.round( (imgItems-1) * Math.random() );
    var handle=document.getElementById("homeimage");
    if (handle) 
	{
	content = "../images/DBimages/" + homepageImgs[randomNumber]
	handle.src = content;
	handle.alt = homepageImgs[randomNumber];
	}
    // change to next banner every 6 seconds - clearTimeout(imageRotator)
    clearTimeout(adID); 
    adID=setTimeout('imageRotator("start")', 6000);
    }
  else if (Direction =="pause")
	{	    
	clearTimeout(adID);    
	adID=setTimeout('imageRotator("start")',10000);
	}
    
  else
	{
	var handle=document.getElementById("homeimage");
	var test = handle.src.replace("http://www.trlib.org/images/DBimages/","");
	for (aIndex=0; aIndex <= imgItems-1;aIndex ++)
	  {
	  if (homepageImgs[aIndex] == test)
	    {
	    flag = 1;
	    switch (Direction)
		{
		case "back":
		  if (aIndex-1 < 0)
		    {
		    content = "../images/DBimages/" + homepageImgs[homepageImgs.length - 1]
		    handle.src = content;
		    handle.alt = homepageImgs[homepageImgs.length - 1];
		    }
		  else
		    {
		    content = "/images/DBimages/" + homepageImgs[aIndex-1]
		    handle.src = content;
		    handle.alt = homepageImgs[aIndex-1];
		    }
                  break;
		case "next":
		  if (aIndex +1 > imgItems-1)
		    {
		    content = "/images/DBimages/" + homepageImgs[0]
		    handle.src = content;
		    handle.alt = homepageImgs[0];
		    }
		  else
		    {
		    content = "/images/DBimages/" + homepageImgs[aIndex+1]
		    handle.src = content;
		    handle.alt = homepageImgs[aIndex+1];
		    }
		  break;
		} // end Switch
	    }  //end if homepageImgs test
	if (flag ==1){break;}
	}  // end for loop
    }  // end 1st if
  } // end function