var nasaImageRotaterCurrentImage;
var nasaImageRotaterTimersArray= new Array();

function nasaImageRotaterGenericPeriodicUpdater(currentImage,rotate,divid)
{

         try
         {

         var j=currentImage;
         //alert("currentImage:"+currentImage);
         new PeriodicalExecuter(function(stop) {
        
         if (rotate=="no"){
		 nasaImageRotaterCurrentImage=j;
         stop.stop();
         }
         else
         {
         nasaImageRotaterTimersArray.push(stop);

                
         if (j < nasaImageRotaterTotalImages)
         {j=j+1;}

         

         if (j< nasaImageRotaterTotalImages)
         {
         $(divid+(j-1)).setStyle({display: 'none',visibility: 'hidden'});
         $(divid+j).setStyle({display: 'block',visibility: 'visible'});
         nasaImageRotaterCurrentImage=j;
         }
         else
         {
           $(divid+(j-1)).setStyle({display: 'none',visibility: 'hidden'});
           j=0;
           $(divid+j).setStyle({display: 'block',visibility: 'visible'});
           nasaImageRotaterCurrentImage=j;
         }
         }
         
       }, 6);

       }
       catch(err)
	{
         if ($('nasa_image_rotater_controls'))
         {
           $('nasa_image_rotater_controls').hide();
         }
	}

}

function nasaImageRotaterStopEventsRotation(divid)
{
  try
  {
  //alert(nasaImageRotaterTimersArray.length);
  for (var i=nasaImageRotaterTimersArray.length-1; i>= 0; i--)
  {
    nasaImageRotaterTimersArray[i].stop();
    nasaImageRotaterTimersArray.pop();
  }
  nasaImageRotaterGenericPeriodicUpdater(0,"no",divid);
  }
   catch(err)
	{
	   if ($('nasa_image_rotater_controls'))
         {
           $('nasa_image_rotater_controls').hide();
         } 
	}
  
}


function nasaImageRotaterStartEventsRotation(divid)
{
  //alert("nasaImageRotaterCurrentImage:"+nasaImageRotaterCurrentImage);
  try
  {
  nasaImageRotaterGenericPeriodicUpdater(nasaImageRotaterCurrentImage,"yes",divid);
  }
  catch (err)
  {
         if ($('nasa_image_rotater_controls'))
         {
           $('nasa_image_rotater_controls').hide();
         }
   }
}


function nasaImageRotaterNextEvent(divid)
{

  try
  {  
  //alert(nasaImageRotaterTimersArray.length);
  for (var i=nasaImageRotaterTimersArray.length-1; i>= 0; i--)
  {
    nasaImageRotaterTimersArray[i].stop();
    nasaImageRotaterTimersArray.pop();
  }
  //alert("nasaImageRotaterCurrentImage:"+nasaImageRotaterCurrentImage);
  
  
  if (((nasaImageRotaterCurrentImage+1) < nasaImageRotaterTotalImages))
  { $(divid+nasaImageRotaterCurrentImage).setStyle({display: 'none',visibility: 'hidden'});
    $(divid+(nasaImageRotaterCurrentImage+1)).setStyle({display: 'block',visibility: 'visible'});
  }
  
  if (nasaImageRotaterCurrentImage == nasaImageRotaterTotalImages-1)
  { $(divid+nasaImageRotaterCurrentImage).setStyle({display: 'none',visibility: 'hidden'});
    $(divid+'0').setStyle({display: 'block',visibility: 'visible'});
  }
  
  if (nasaImageRotaterCurrentImage == nasaImageRotaterTotalImages-1)
  {
     nasaImageRotaterCurrentImage=0;
  }
  else
  {
    nasaImageRotaterCurrentImage=nasaImageRotaterCurrentImage+1;
  }
  
  if ($('nasa_image1'))
  {
  $('nasa_image1').hide();
  }

  if ($('nasa_image2'))
  {
  $('nasa_image2').show();
  }

  }
  catch(err)
	{
         if ($('nasa_image_rotater_controls'))
         {
           $('nasa_image_rotater_controls').hide();
         }
	}
}



function nasaImageRotaterPrevEvent(divid)
{

  try
  {

  //alert(nasaImageRotaterTimersArray.length);
  for (var i=nasaImageRotaterTimersArray.length-1; i>= 0; i--)
  {
    nasaImageRotaterTimersArray[i].stop();
    nasaImageRotaterTimersArray.pop();
  }
  //alert("nasaImageRotaterCurrentImage:"+nasaImageRotaterCurrentImage);
    
  if ((nasaImageRotaterCurrentImage < nasaImageRotaterTotalImages) && (nasaImageRotaterCurrentImage > 0))
  { $(divid+nasaImageRotaterCurrentImage).setStyle({display: 'none',visibility: 'hidden'});
    $(divid+(nasaImageRotaterCurrentImage-1)).setStyle({display: 'block',visibility: 'visible'});
  }
  
  if (nasaImageRotaterCurrentImage == 0)
  { $(divid+nasaImageRotaterCurrentImage).setStyle({display: 'none',visibility: 'hidden'});
    $(divid+(nasaImageRotaterTotalImages-1)).setStyle({display: 'block',visibility: 'visible'});
  }
  
  if (nasaImageRotaterCurrentImage == 0)
  {
     nasaImageRotaterCurrentImage=nasaImageRotaterTotalImages-1;
  }
  else
  {
    nasaImageRotaterCurrentImage=nasaImageRotaterCurrentImage-1;
  }
  

  if ($('nasa_image1'))
  {
  $('nasa_image1').hide();
  }

  if ($('nasa_image2'))
  {
  $('nasa_image2').show();
  }

  }
  catch(err)
	{
         if ($('nasa_image_rotater_controls'))
         {
           $('nasa_image_rotater_controls').hide();
         }
	    
	}


}