//*** This code is copyright 2004 by Gavin Kistner, !@phrogz.net
//*** It is covered under the license viewable at http://phrogz.net/JS/_ReuseLicense.txt
//*** Reuse or modification is free provided you abide by the terms of that license.
//*** (Including the first two lines above in your source code satisfies the conditions.)
//  ---------------------------------------------------------------------------
AttachEvent(window, 'load', function () {
  function Init() {
    //DebugOut("Draggable.Init()",1);
    var els = document.getElementsByTagName('*');
    if ((!els || els.length == 0) && document.all) els = document.all;
    for (var i = els.length - 1; i >= 0; i--) {
      var el = els[i];
      if (!HasClass(el, 'draggable')) continue;
      //DebugOut("Draggable.Init() -- found an element to drag: "+el.tagName,2);
      AttachEvent(el, 'mousedown', StartDrag, false);
      AttachEvent(el, 'selectstart', PreventDefault, false);
    }
  }

  //  -------------------------------------------------------------------------
  function StartDrag(evt) {
    //DebugOut("StartDrag("+evt+")",1);
    if (!evt && window.event) evt = event;
    if (!evt) return alert("ERROR: Can't find an event object for Start Drag!");
    var obj = evt.currentTarget || evt.srcElement;
    while (obj && !HasClass(obj, 'draggable')) obj = obj.parentNode;
    if (!obj) return alert("ERROR: Can't find the object to drag.");
    window.draggableInfo = {
      obj: obj,
      x: parseInt(obj.style.left, 10) - evt.clientX,
      y: parseInt(obj.style.top, 10) - evt.clientY
    };
    AttachEvent(document.body, 'mousemove', TrackDrag, false);
    AttachEvent(document.body, 'mouseup', StopDrag, false);
    AttachEvent(document.body, 'selectstart', PreventDefault, false);
    AddClass(obj, 'draggingNOW');
  }

  //  -------------------------------------------------------------------------
  function TrackDrag(evt) {
    //DebugOut("TrackDrag("+evt+")",3);
    if (!evt && window.event) evt = event;
    if (!evt) return alert("ERROR: Can't find an event object for Start Drag!");
    if (!window.draggableInfo) return alert("ERROR: Where's my draggableInfo?!");
    var obj = draggableInfo.obj;
    obj.style.left = evt.clientX + draggableInfo.x + 'px';
    obj.style.top = evt.clientY + draggableInfo.y + 'px';
  }

  //  -------------------------------------------------------------------------
  function StopDrag() {
    //DebugOut("StopDrag()",2);
    if (window.draggableInfo) KillClass(draggableInfo.obj, 'draggingNOW');
    window.draggableInfo = null;
    DetachEvent(document.body, 'mousemove', TrackDrag, false);
    DetachEvent(document.body, 'mouseup', StopDrag, false);
    DetachEvent(document.body, 'selectstart', PreventDefault, false);
  }

  Init();
},
false);

//debugLevel=1;