scrollitems = {};
scrollbox.speed=100;
function scrollbox(wnId,lyrId,cntId)
{
    this.id=wnId;scrollitems[this.id]=this;
    this.animString="scrollitems."+this.id;
    this.load(lyrId,cntId);
}
    scrollbox.loadLayer=function(wnId,id,cntId)    {        if(scrollitems[wnId])scrollitems[wnId].load(id,cntId);    };
    
    scrollbox.prototype.load=function(lyrId,cntId){if(!document.getElementById)return;var wndo,lyr;if(this.lyrId){lyr=document.getElementById(this.lyrId);lyr.style.visibility="hidden";}lyr=document.getElementById(lyrId);wndo=document.getElementById(this.id);lyr.style.top=this.y=0;lyr.style.left=this.x=0;this.maxY=(lyr.offsetHeight-wndo.offsetHeight>0)?lyr.offsetHeight-wndo.offsetHeight:0;this.wd=cntId?document.getElementById(cntId).offsetWidth:lyr.offsetWidth;this.maxX=(this.wd-wndo.offsetWidth>0)?this.wd-wndo.offsetWidth:0;this.lyrId=lyrId;lyr.style.visibility="visible";this.on_load();this.ready=true;};scrollbox.prototype.on_load=function(){};scrollbox.prototype.shiftTo=function(lyr,x,y){if(!lyr.style||!scrollbox.scrdy)return;lyr.style.left=(this.x=x)+"px";lyr.style.top=(this.y=y)+"px";};scrollbox.GeckoTableBugFix=function(){var ua=navigator.userAgent;if(ua.indexOf("Gecko")>-1&&ua.indexOf("Firefox")==-1&&ua.indexOf("Safari")==-1&&ua.indexOf("Konqueror")==-1){scrollbox.hold=[];for(var i=0;arguments[i];i++){if(scrollitems[arguments[i]]){var wndo=document.getElementById(arguments[i]);var holderId=wndo.parentNode.id;var holder=document.getElementById(holderId);document.body.appendChild(holder.removeChild(wndo));wndo.style.zIndex=1000;var pos=getPageOffsets(holder);wndo.style.left=pos.x+"px";wndo.style.top=pos.y+"px";scrollbox.hold[i]=[arguments[i],holderId];}}window.addEventListener("resize",scrollbox.rePositionGecko,true);}};scrollbox.rePositionGecko=function(){if(scrollbox.hold){for(var i=0;scrollbox.hold[i];i++){var wndo=document.getElementById(scrollbox.hold[i][0]);var holder=document.getElementById(scrollbox.hold[i][1]);var pos=getPageOffsets(holder);wndo.style.left=pos.x+"px";wndo.style.top=pos.y+"px";}}};function getPageOffsets(el){var left=el.offsetLeft;var top=el.offsetTop;
 if(el.offsetParent&&el.offsetParent.clientLeft||el.offsetParent.clientTop)
        {left+=el.offsetParent.clientLeft;top+=el.offsetParent.clientTop;}
    while(el=el.offsetParent){left+=el.offsetLeft;top+=el.offsetTop;}
    return{x:left,y:top};};
    scrollbox.scrdy=true;
    
scrollbox.slideDur = 500; // duration of glide

// intermediary functions needed to prevent errors before page loaded 
scrollbox.scrollBy = function(wnId, x, y, dur) {
  if ( scrollitems[wnId] ) scrollitems[wnId].glideBy(x, y, dur);
}

scrollbox.scrollTo = function(wnId, x, y, dur) {
  if ( scrollitems[wnId] ) scrollitems[wnId].glideTo(x, y, dur);
}

// Resources for time-based slide algorithm: 
//  DHTML chaser tutorial at DHTML Lab - www.webreference.com/dhtml	
//  and cbe_slide.js from	www.cross-browser.com by Mike Foster
scrollbox.prototype.glideBy = function(dx, dy, dur) {
  if ( !document.getElementById || this.sliding ) return;
  this.slideDur = dur || scrollbox.slideDur;
  this.destX = this.destY = this.distX = this.distY = 0;
  this.lyr = document.getElementById(this.lyrId);
  this.startX = this.x; this.startY = this.y;
  if (dy < 0) this.distY = (this.startY + dy >= -this.maxY)? dy: -(this.startY  + this.maxY);
  else if (dy > 0) this.distY = (this.startY + dy <= 0)? dy: -this.startY;
  if (dx < 0) this.distX = (this.startX + dx >= -this.maxX)? dx: -(this.startX + this.maxX);
  else if (dx > 0) this.distX = (this.startX + dx <= 0)? dx: -this.startX;
  this.destX = this.startX + this.distX; this.destY = this.startY + this.distY;
  this.slideTo(this.destX, this.destY);
}

scrollbox.prototype.glideTo = function(destX, destY, dur) {
  if ( !document.getElementById || this.sliding) return;
  this.slideDur = dur || scrollbox.slideDur;
  this.lyr = document.getElementById(this.lyrId); 
  this.startX = this.x; this.startY = this.y;
  this.destX = -Math.max( Math.min(destX, this.maxX), 0);
  this.destY = -Math.max( Math.min(destY, this.maxY), 0);
  this.distY = this.destY - this.startY;
  this.distX =  this.destX - this.startX;
  this.slideTo(this.destX, this.destY);
}

scrollbox.prototype.slideTo = function(destX, destY) {
  this.per = Math.PI/(2 * this.slideDur); this.sliding = true;
	this.slideStart = (new Date()).getTime();
	this.aniTimer = setInterval(this.animString + ".doSlide()",10);
  this.on_slide_start(this.startX, this.startY);
}

scrollbox.prototype.doSlide = function() {
	var elapsed = (new Date()).getTime() - this.slideStart;
	if (elapsed < this.slideDur) {
		var x = this.startX + this.distX * Math.sin(this.per*elapsed);
		var y = this.startY + this.distY * Math.sin(this.per*elapsed);
    this.shiftTo(this.lyr, x, y); this.on_slide(x, y);
	} else {	// if time's up
    clearInterval(this.aniTimer); this.sliding = false;
		this.shiftTo(this.lyr, this.destX, this.destY);
    this.lyr = null; this.on_slide_end(this.destX, this.destY);
	}
}

scrollbox.prototype.on_slide_start = function() {}
scrollbox.prototype.on_slide = function() {}
scrollbox.prototype.on_slide_end = function() {}