window.addEvent('domready', function() {
	
	/* ----------Config Vars----------- */
	var slideTimer = 9000;  //time between slides (1 second = 1000), a.k.a. the interval duration
	var transitionTime = 750; //transition time (1 second = 1000)
	var items = $$('.slide_item');  //Get array of elements for sliding
	var prevBtn = $('prevbtn');
	var playBtn = $('playbtn');
	var nextBtn = $('nextbtn');
	var itemNum = 0;  //initialize a variable to hold the current slide index
	var isPaused = 0;
	
	/* --------end config vars-------- */
	
	//Setup positions
	items.each(function(element, index) {
		
		//since the viewer obviously has javascript on, we can remove the 'first_item' class
		if(index == 0){
			element.removeClass('first_item');
			element.setStyle('left', "0");
		}
		else{
			element.setStyle('left', "988px");
		}
	
	});
	
	var numItems = items.length;  //get number of slider items
	//end setup
	
	
	
	//Slider Stuff
	var slideForward = function(){ 
	
		//get item to slide out
		var curItem = items[itemNum];  
		
		//change index
		if(itemNum < (numItems - 1)){
			itemNum++; 
		}
		else{
			itemNum = 0;
		}
		
		//now get item to slide in using new index
		var newItem = items[itemNum];
		
		
		//set up our animation stylings for out and in motions (note:  Fx.Styles does NOT exist in moo 1.2, so we must use Fx.Morph or Fx.Tween)
		var item_in = new Fx.Morph(newItem, {
			     duration: transitionTime, 
			     transition: Fx.Transitions.Quad.easeInOut, 
			     wait:false
		});
		
		var item_out = new Fx.Morph(curItem, {
			     duration: transitionTime, 
			     transition: Fx.Transitions.Quad.easeInOut, 
			     wait:false
		});
		
		//we will set a beginning value here
		//this is so that it gives the illusion of continuous motion from one direction, even after the first cycle of items
		item_in.start({
		'left': [988, 0]
		});
		
		//no beginning values needed, since we always want to push the old item out to the left
		item_out.start({
		'left': '-988'
		});
		
	};
		
		
	var slideBackward = function(){ 
	
		//get item to slide out
		var curItem = items[itemNum];  
		
		//change index for reverse movement
		if(itemNum > 0){
			itemNum--; 
		}
		else{
			itemNum = (numItems - 1);
		}
		
		//now get item to slide in using new index
		var newItem = items[itemNum];
		
		
		var item_in = new Fx.Morph(newItem, {
			     duration: transitionTime, 
			     transition: Fx.Transitions.Quad.easeInOut, 
			     wait:false
		});
		
		var item_out = new Fx.Morph(curItem, {
			     duration: transitionTime, 
			     transition: Fx.Transitions.Quad.easeInOut, 
			     wait:false
		});
		
		
		//we will set a beginning value here too, but this time to make it come from left to right
		item_in.start({
		'left': [-988, 0]
		});
		
		//no beginning values needed
		item_out.start({
		'left': '988'
		});
		
	};
	//end slideBackward
		
		
	//call the slider function periodically
	var theTimer = slideForward.periodical(slideTimer, this); 
	
    var initNextButton = function(){    
        if (nextBtn==null)
        {
            //alert("next button was null...trying again in 1 second");
            setTimeout("initNextButton()", 1000);
        }
        else
        {
	        nextBtn.addEvent('click', function(){
		        if(isPaused == 0){
			        $clear(theTimer);
			        theTimer = slideForward.periodical(slideTimer);
		        }
		        slideForward();
	        });        
	    }
    };
    initNextButton();	
	
	
	
    var initPrevButton = function(){    
        if (prevBtn==null)
        {
            //alert("prev button was null...trying again in 1 second");
            setTimeout("initPrevButton()", 1000);
        }
        else
        {
	        prevBtn.addEvent('click', function(){
		        if(isPaused == 0){
			        $clear(theTimer);
			        theTimer = slideForward.periodical(slideTimer);
		        }				     
		        slideBackward();
	        });
	    }
    };
    initPrevButton();		

    var initPlayButton = function(){    
        if (playBtn==null)
        {
            //alert("play button was null...trying again in 1 second");
            setTimeout("initPlayButton()", 1000);
        }
        else
        {
	        playBtn.addEvent('click', function(){
		        if(isPaused == 0){
			        isPaused = 1;
			        $clear(theTimer);
			        document.getElementById('playbtnimg').src='http://images.medicinenet.com/images/slider module/play_large_green.gif';
		        }
		        else{
			        isPaused = 0;
			        slideForward();
			        theTimer = slideForward.periodical(slideTimer); 
			        document.getElementById('playbtnimg').src='http://images.medicinenet.com/images/slider module/pause_large_green.gif';
		        }
	         });
	    }
    };
    initPlayButton();	
	
});