dw_scrollObjs = {};
dw_scrollObj.speed=100; // default speed for mouseover scrolling
//  constructor arguments: id of layer containing scrolling layers (clipped layer), id of layer to scroll, 
//  id of table or other element that scrolling content is nested in. 
//  ns6+/moz need that extra container to get width for horizontal scrolling.
//  (not needed for vertical scrolling)
function dw_scrollObj(wnId,lyrId,cntId) {
  this.id = wnId; dw_scrollObjs[this.id] = this;
  this.animString = "dw_scrollObjs." + this.id;
  this.load(lyrId, cntId);
}

dw_scrollObj.loadLayer = function(wnId,id,cntId) {
  if (dw_scrollObjs[wnId]) dw_scrollObjs[wnId].load(id,cntId);
}

dw_scrollObj.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; // hold id of currently visible layer
  lyr.style.visibility = "visible";
  this.on_load(); this.ready=true;
}

dw_scrollObj.prototype.on_load = function() {}

dw_scrollObj.prototype.shiftTo = function(lyr, x, y) {
  if (!lyr.style) return;
  lyr.style.left = (this.x = x) + "px";
  lyr.style.top = (this.y = y) + "px";
}

// remove layers from table for ns6+/mozilla (needed for scrolling inside tables)
dw_scrollObj.GeckoTableBugFix = function() {
  var ua = navigator.userAgent;
  if (ua.indexOf("Gecko")>-1 && ua.indexOf("Firefox")==-1 && ua.indexOf("Safari")==-1 && ua.indexOf("Konqueror")==-1) {
    dw_scrollObj.hold = []; // holds id's of wndo and its container
    for (var i=0; arguments[i]; i++) {
      if (dw_scrollObjs[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";
        dw_scrollObj.hold[i] = [arguments[i],holderId];
      }
    }
    window.addEventListener("resize",dw_scrollObj.rePositionGecko,true);
  }
}

dw_scrollObj.rePositionGecko = function() {
  if (dw_scrollObj.hold) {
    for (var i=0;dw_scrollObj.hold[i];i++) {
      var wndo = document.getElementById(dw_scrollObj.hold[i][0]);
      var holder = document.getElementById(dw_scrollObj.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
  };
}