/*------------------ MyScroller -----------------*/

function ulscroller(objId,speed){
	
	  this.name = objId;
      this.speed = speed;
      this.initList();
      this.setSpeed(this.speed);
	  return this;
	
}
ulscroller.prototype = {

	  name:"",
      speed:0,
      currPos:0,
      totalHeight:'0px',
      action:false,
      
      /**
       * Get all list elements and move them.
       */             
      scrollList : function () {
        if(this.action) {     
          var list = $(this.name); 
	 	  var listElements = list.getElementsByTagName('li'); 
          var h = listElements[this.currPos].offsetHeight;
          for(var i=0; i<listElements.length; i++) {
            var currE = listElements[i];      
            this.moveElement(currE,-h);
          }
          this.currPos ++;
          if(this.currPos >= listElements.length) {
            this.currPos = 0;
          }
        }
      },
      
      /**
       * Move up an element if it's not the first. Else put it to the end of 
       * the list.       .
       */             
      moveElement : function(element, step) {
        var tempH = this.totalHeight; // create because afterFinish method can't 
                                      //used this.totalHeight ?!
        if(element.style.top.split("px")[0] <= 0) {
         new Effect.Opacity(element, { from: 1.0, to: 0, duration: 0.5, 
           afterFinish:function(){
              element.style.top=tempH-element.offsetHeight+'px';
              Effect.Appear(element, { duration: 0.5 });
           }
         });
        } else {   
           new Effect.Move(element, { x: 0, y: step, mode: 'relative'});
        }
      },
    
      /**
       * init list elements positions.
       */             
      initList : function () {
        var list = $(this.name);
        var elements = $$('#' + list.id + ' li');
        
        var pos = 0;
        for(var i=0; i<elements.length; i++) {
          elements[i].style.top = pos + 'px'; 
          pos = pos + elements[i].offsetHeight;
        }
        this.totalHeight = pos;
      },
      
      /**
       * Allow to adjust the scrolling speed
       *  speed : speed in milliseconds
       */             
      setSpeed : function(speed) {
        setInterval(this.name + '.scrollList()',speed);
      },
      
      /**
       * Allow to start the list scrolling
       */             
      startScrolling : function (){
        this.action = true;
      },
      
      /**
       * Allow to stop the list scrolling
       */
      stopScrolling : function() {
        this.action = false;
      } 
    }
    
// Hack to draw a correct list when Javascript is disabled
document.documentElement.className+=" hasJS";