// JavaScript Document

//We wrap all the code in an object so that it doesn't interfere with any other code
var scroller = {
  init:   function()
	{
	   //collect the variables
	   //var alturaArea = document.getElementById("imgRegHeight").clientHeight-2;
		if(document.getElementById("MB_container")!=null)
		{
			document.getElementById("MB_container").style.height = 266;//alturaArea.toString()+"px";
			document.getElementById("MB_scrollArea").style.height =  266;//alturaArea.toString()+"px";
			
			scroller.docH = document.getElementById("MB_content").offsetHeight;
			scroller.contH = document.getElementById("MB_container").offsetHeight;
			scroller.scrollAreaH = document.getElementById("MB_scrollArea").offsetHeight;
		
			mostraCamadas();
			
			if(scroller.docH<=scroller.contH)
			{
				document.getElementById("MB_scrollArea").style.display='none';
				document.getElementById("imgRegHeight").style.width=1;
				document.getElementById("imgReg").style.width=0;
				document.getElementById("MB_container").style.width=239;
				document.getElementById("MB_content").style.width=239;
			}

			//calculate height of scroller and resize the scroller div
			//(however, we make sure that it isn't to small for long pages)
			scroller.scrollH = 61;//(scroller.contH * scroller.scrollAreaH) / scroller.docH;
			//if(scroller.scrollH < 15) scroller.scrollH = 15;
			document.getElementById("MB_scroller").style.height = Math.round(scroller.scrollH) + "px";
			//what is the effective scroll distance once the scoller's height has been taken into account
			scroller.scrollDist = Math.round(scroller.scrollAreaH-scroller.scrollH);
			//make the scroller div draggable
			Drag.init(document.getElementById("MB_scroller"),null,0,0,-1,scroller.scrollDist);
			//add ondrag function
			document.getElementById("MB_scroller").onDrag = function (x,y) {
			var scrollY = parseInt(document.getElementById("MB_scroller").style.top);
			var docY = 0 - (scrollY * (scroller.docH - scroller.contH) / scroller.scrollDist);
			document.getElementById("MB_content").style.top = docY + "px";
		}
	}
  }
}

window.onload = scroller.init;