//*****************************************************************************
// Do not remove this notice.
//
// Copyright 2001 by Mike Hall.
// See http://www.brainjar.com for terms of use.
//*****************************************************************************
function Browser() {
  this.isIE = false;
  this.isNS = false;
  if (navigator.userAgent.indexOf("MSIE") >= 0) {
    this.isIE = true;
  }
  else if (navigator.userAgent.indexOf("Gecko") >= 0 || navigator.userAgent.indexOf("Netscape6/") >= 0) {
    this.isNS = true;
  }
}

var browser = new Browser();
var dragObj = new Object();
dragObj.zIndex = 0;

function dragStart(event, id) {
  var el;
  var x, y;
  if (id) {
    dragObj.elNode = document.getElementById(id);
  }
  else {
    if (browser.isIE)
      dragObj.elNode = window.event.srcElement;
    else if (browser.isNS)
      dragObj.elNode = event.target;
    if (dragObj.elNode.nodeType == 3)
      dragObj.elNode = dragObj.elNode.parentNode;
  }
  if (browser.isIE) {
    x = window.event.clientX + document.documentElement.scrollLeft
      + document.body.scrollLeft;
    y = window.event.clientY + document.documentElement.scrollTop
      + document.body.scrollTop;
  }
  else if (browser.isNS) {
    x = event.clientX + window.scrollX;
    y = event.clientY + window.scrollY;
  }
  dragObj.cursorStartX = x;
  dragObj.cursorStartY = y;
  dragObj.elStartLeft = parseInt(dragObj.elNode.style.left, 10);
  dragObj.elStartTop = parseInt(dragObj.elNode.style.top, 10);

  if (isNaN(dragObj.elStartLeft)) dragObj.elStartLeft = dragObj.elNode.offsetLeft;
  if (isNaN(dragObj.elStartTop)) dragObj.elStartTop = dragObj.elNode.offsetTop;
  dragObj.elNode.style.zIndex = ++dragObj.zIndex;
  if (browser.isIE) {
    document.attachEvent("onmousemove", dragGo);
    document.attachEvent("onmouseup", dragStop);
    window.event.cancelBubble = true;
    window.event.returnValue = false;
  }
  else if (browser.isNS) {
    document.addEventListener("mousemove", dragGo, true);
    document.addEventListener("mouseup", dragStop, true);
    event.preventDefault();
  }
}

function dragGo(event) {
  var x, y;
  if (browser.isIE) {
    x = window.event.clientX + document.documentElement.scrollLeft
      + document.body.scrollLeft;
    y = window.event.clientY + document.documentElement.scrollTop
      + document.body.scrollTop;
  }
  else if (browser.isNS) {
    x = event.clientX + window.scrollX;
    y = event.clientY + window.scrollY;
  }
  dragObj.elNode.style.left = (dragObj.elStartLeft + x - dragObj.cursorStartX) + "px";
  dragObj.elNode.style.top = (dragObj.elStartTop + y - dragObj.cursorStartY) + "px";
  if (browser.isIE) {
    window.event.cancelBubble = true;
    window.event.returnValue = false;
  }
  else if (browser.isNS)
    event.preventDefault();
}

function dragStop(event) {
  if (browser.isIE) {
    document.detachEvent("onmousemove", dragGo);
    document.detachEvent("onmouseup", dragStop);
  }
  else if (browser.isNS) {
    document.removeEventListener("mousemove", dragGo, true);
    document.removeEventListener("mouseup", dragStop, true);
  }
}