//==============================
// global variables
//==============================
var pic_count=0;
var lastpic=0;
var back_button=document.getElementById('backbut');
var play_button=document.getElementById('playbut');
var next_button=document.getElementById('nextbut');
var slide_button=document.getElementById('slidebut');
var thumbs_button=document.getElementById('thumbbut');
var thumbnail_win=document.getElementById('thumbwin');
var slide_win=document.getElementById('slidewin');
var stop_button=document.getElementById('stopbut');

// start slide show
function slide_show()
	{
	  thumbnail_win.style.visibility='hidden';
	  slide_win.style.visibility='visible';
	  back_button.style.visibility='visible';
	  next_button.style.visibility='visible';
	  play_button.style.visibility='visible';
	  slide_button.style.visibility='hidden';
	  thumbs_button.style.visibility='visible';
	  next_button.onclick=next_img_slide;
	  back_button.onclick=prev_img_slide;
	  play_button.onclick=pl_slide;
	  
	  return false;	
	}
//displays thumbnails	
function thumb_show()
	{
	  document.getElementById('thumbwin').style.visibility='visible';
	  document.getElementById('slidewin').style.visibility='hidden';
	  back_button.style.visibility='hidden';
	  next_button.style.visibility='hidden';
	  play_button.style.visibility='hidden';
	  slide_button.style.visibility='visible';
	  thumbs_button.style.visibility='hidden';
	  
	  return false	
	}
   
//	selects pic based on next button
	
function next_img_slide()
     {
       var displayslide=document.getElementById('slidedisplay');
	   var piclabel=document.getElementById('caption');
	   var labeltext;
	   pic_count=pic_count+1;
	   check_count(pic_count);
	   labeltext=caps[pic_count]+"; (slide "+pic_count+")";
	   piclabel.innerHTML=labeltext;
	   displayslide.src=pics[pic_count] ; 
	   return false;         
     }

function prev_img_slide()
     {
       var displayslide=document.getElementById('slidedisplay');
	   var piclabel=document.getElementById('caption');
	   var labeltext;
	   pic_count=pic_count-1;
	   check_count(pic_count);
	   labeltext=caps[pic_count]+"; (slide "+pic_count+")";
	   piclabel.innerHTML=labeltext;
	   displayslide.src=pics[pic_count] ; 
	   return false;         
     }	
     
 // checks for valid count displays appropriate message if outside
 //  array size 
 
	function check_count(count)
	 {
	  if (count<0)
	   {
	    alert("this is the first picture");
		pic_count=0;
	   }
	  if (count>=pics.length)
	   {
	    alert("you have reached the last picture");
		pic_count=0;
	   }	
	 }
	
//  runs auto slides	 
	  
function pl_slide()
  {
    var slide=document.getElementById('slidedisplay');
	var label=document.getElementById('caption');
	var labeltext;
	back_button.style.visibility='hidden';
	next_button.style.visibility='hidden';
	play_button.style.visibility='hidden';
	thumbs_button.style.visibility='hidden';
	stop_button.onclick=st_slide;
	stop_button.style.visibility='visible';
	pic_count++;
	if (pic_count>=pics.length)
	  {
	   aw=clearTimeout(aw);
	   pic_count=0;
	   back_button.style.visibility='visible';
	   next_button.style.visibility='visible';
	   play_button.style.visibility='visible';
	   slide_button.style.visibility='hidden';
	   thumbs_button.style.visibility='visible';
	   stop_button.style.visibility='hidden';
	   labeltext=caps[pic_count]+"; (slide "+pic_count+")";
	   label.innerHTML=labeltext;
	   slide.src=pics[pic_count];
	  }
	else
	  {
	   labeltext=caps[pic_count]+"; (slide "+pic_count+")";
	   label.innerHTML=labeltext;
	   slide.src=pics[pic_count];
	   aw=setTimeout('pl_slide()',2500);
	  }
  }
  
function st_slide()
	{
	  pic_count=pics.length;
	  pl_slide();
	}
  
function thumb_image()
	{
	  //get list of images in thumbnail window
	  imglist=document.getElementById('thumbwin').getElementsByTagName('img');
	  //set onclick attribute to each image
	  for (i=0;i<imglist.length;i++)
	    {		 
		  //imglist[i].setAttribute('onclick','sh_thumb(this)');
		  imglist[i].onclick=function() {sh_thumb(this); return false;}
	    }	  	
	}
	
function sh_thumb(a)
	{
	  //thumb_source=a.src;
	  thumb_source=a.getAttribute('src');
	  b=thumb_source.indexOf("sm");
	  if (b ==-1)
	     {
		   thumb_source=thumb_source.slice(thumb_source.lastIndexOf('/')+1,thumb_source.length);
		   new_source="sm/"+thumb_source;
		   a.setAttribute('src',new_source)
		   return false;
	     }
	    else
	     {
		   new_source=thumb_source.slice(thumb_source.lastIndexOf('/')+1,thumb_source.length);
		   a.src=new_source;   
		   return false;
	     }
	  return false;	   
	}
//imglist[i].setAttribute('src','../'+pics[i]);
function attach()
	{
	  thumbs_button.onclick=thumb_show;
	  slide_button.onclick=slide_show;
	  thumb_image();	
	}