var _startX = 0;			// mouse starting positions
var _startY = 0;
var _offsetX = 0;			// current element offset
var _offsetY = 0;
var _dragElement;			// needs to be passed from OnMouseDown to OnMouseMove
var _oldZIndex = 0;			// we temporarily increase the z-index during drag
var _screenWidth, _screenHeight;
var _width;
var _height;
var _debug;
var _scrollHeight;


InitDragDrop();

function InitDragDrop()
{
	document.onmousedown = OnMouseDown;
	document.onmouseup = OnMouseUp;
}

function OnMouseDown(e)
{

	close(e);
	// IE is retarded and doesn't pass the event object
	if (e == null)
		e = window.event;

	// IE uses srcElement, others use target
	var target = e.target != null ? e.target : e.srcElement;

	_debug = $('debug');

	// for IE, left click == 1
	// for Firefox, left click == 0
	if ((e.button == 1 && window.event != null ||
		e.button == 0) &&
		HasClassName(target,'drag'))
	{
		// grab the mouse position
		_startX = e.clientX;
		_startY = e.clientY;

		// get the screen height and width

		if (parseInt(navigator.appVersion)>3) {
		 	if (navigator.appName=="Netscape") {
		  		_screenWidth = window.innerWidth - 20;
		  		_screenHeight = window.innerHeight;
		 	}
		 	if (navigator.appName.indexOf("Microsoft")!=-1) {
		  		_screenWidth = document.body.offsetWidth;
		  		_screenHeight = document.body.offsetHeight;
			}
		}
		// grab the clicked element's position
		_offsetX = ExtractNumber(target.style.left);
		_offsetY = ExtractNumber(target.style.top);

		_width = target.offsetWidth;
		_height = target.offsetHeight;

		// bring the clicked element to the front while it is being dragged
		_oldZIndex = target.style.zIndex;
		target.style.zIndex = 10000;

		// we need to access the element in OnMouseMove
		_dragElement = target;

		// tell our code to start moving the element with the mouse
		document.onmousemove = OnMouseMove;

		// cancel out any text selections
		document.body.focus();

		// prevent text selection in IE
		document.onselectstart = function () { return false; };

		// prevent text selection (except IE)
		return false;
	}
}

function ExtractNumber(value)
{
	var n = parseInt(value);

	return n == null || isNaN(n) ? 0 : n;
}

function OnMouseMove(e)
{
	if (e == null)
		var e = window.event;

	AddClassName(_dragElement,'transparent');

	var oldPosX = ExtractNumber(_dragElement.style.left);
	var oldPosY = ExtractNumber(_dragElement.style.top);
	var posX    = (_offsetX + e.clientX - _startX);
	var posY    = (_offsetY + e.clientY - _startY);
	var right   = ExtractNumber(_dragElement.style.left) + _width;
	var bottom  = ExtractNumber(_dragElement.style.top) + _height;

	if (posX < 0) {
		posX = 0;
	}
	if (posX >= oldPosX && right >= _screenWidth) {
		posX = _screenWidth - _width ;
	}

	if (posY < 0) {
		posY = 0;
	}
	if (posY >= oldPosY && bottom >= _screenHeight) {
		posY = _screenHeight - _height ;
	}

	// this is the actual "drag code"
	_dragElement.style.left = posX + 'px';
	_dragElement.style.top = posY + 'px';

	if (_dragElement.offsetWidth > _width) {
		_dragElement.style.width = _width;
	}
	document.cookie = 'ppkcookie1=testcookie; expires=Thu, 2 Aug 2001 20:47:11 UTC; path=/';
}

function OnMouseUp(e)
{
	if (_dragElement != null)
	{
		_dragElement.style.zIndex = _oldZIndex;

		// we're done with these events until the next OnMouseDown
		document.onmousemove = null;
		document.onselectstart = null;

		RemoveClassName(_dragElement,'transparent');
		// this is how we know we're not dragging
		_dragElement = null;

	}
}

function createCookie(name,value,days) {
	if (days) {
		var date = new Date();
		date.setTime(date.getTime()+(days*24*60*60*1000));
		var expires = "; expires="+date.toGMTString();
	}
	else var expires = "";
	document.cookie = name+"="+value+expires+"; path=/";
}

// this is simply a shortcut for the eyes and fingers
/*function $(id)
{
	return document.getElementById(id);
}*/

// ----------------------------------------------------------------------------
// HasClassName
//
// Description : returns boolean indicating whether the object has the class name
//    built with the understanding that there may be multiple classes
//
// Arguments:
//    objElement              - element to manipulate
//    strClass                - class name to add
//
function HasClassName(objElement, strClass)
   {

   // if there is a class
   if ( objElement.className )
      {

      // the classes are just a space separated list, so first get the list
      var arrList = objElement.className.split(' ');

      // get uppercase class for comparison purposes
      var strClassUpper = strClass.toUpperCase();

      // find all instances and remove them
      for ( var i = 0; i < arrList.length; i++ )
         {

         // if class found
         if ( arrList[i].toUpperCase() == strClassUpper )
            {

            // we found it
            return true;

            }

         }

      }

   // if we got here then the class name is not there
   return false;

   }
//
// HasClassName
// ----------------------------------------------------------------------------


// ----------------------------------------------------------------------------
// AddClassName
//
// Description : adds a class to the class attribute of a DOM element
//    built with the understanding that there may be multiple classes
//
// Arguments:
//    objElement              - element to manipulate
//    strClass                - class name to add
//
function AddClassName(objElement, strClass, blnMayAlreadyExist)
   {

   // if there is a class
   if ( objElement.className )
      {

      // the classes are just a space separated list, so first get the list
      var arrList = objElement.className.split(' ');

      // if the new class name may already exist in list
      if ( blnMayAlreadyExist )
         {

         // get uppercase class for comparison purposes
         var strClassUpper = strClass.toUpperCase();

         // find all instances and remove them
         for ( var i = 0; i < arrList.length; i++ )
            {

            // if class found
            if ( arrList[i].toUpperCase() == strClassUpper )
               {

               // remove array item
               arrList.splice(i, 1);

               // decrement loop counter as we have adjusted the array's contents
               i--;

               }

            }

         }

      // add the new class to end of list
      arrList[arrList.length] = strClass;

      // add the new class to beginning of list
      //arrList.splice(0, 0, strClass);

      // assign modified class name attribute
      objElement.className = arrList.join(' ');

      }
   // if there was no class
   else
      {

      // assign modified class name attribute
      objElement.className = strClass;

      }

   }
//
// AddClassName
// ----------------------------------------------------------------------------


// ----------------------------------------------------------------------------
// RemoveClassName
//
// Description : removes a class from the class attribute of a DOM element
//    built with the understanding that there may be multiple classes
//
// Arguments:
//    objElement              - element to manipulate
//    strClass                - class name to remove
//
function RemoveClassName(objElement, strClass)
   {

   // if there is a class
   if ( objElement.className )
      {

      // the classes are just a space separated list, so first get the list
      var arrList = objElement.className.split(' ');

      // get uppercase class for comparison purposes
      var strClassUpper = strClass.toUpperCase();

      // find all instances and remove them
      for ( var i = 0; i < arrList.length; i++ )
         {

         // if class found
         if ( arrList[i].toUpperCase() == strClassUpper )
            {

            // remove array item
            arrList.splice(i, 1);

            // decrement loop counter as we have adjusted the array's contents
            i--;

            }

         }

      // assign modified class name attribute
      objElement.className = arrList.join(' ');

      }
   // if there was no class
   // there is nothing to remove

   }
//
// RemoveClassName
// ----------------------------------------------------------------------------

function getCookie (name) {
    var dc = document.cookie;
    var cname = name + "=";

    if (dc.length > 0) {
      begin = dc.indexOf(cname);
      if (begin != -1) {
        begin += cname.length;
        end = dc.indexOf("", begin);
        if (end == -1) end = dc.length;
        return unescape(dc.substring(begin, end));
        }
      }
    return null;
}