// Determine browser and version.

function Browser() {

	var ua, s, i;

  	this.isIE    = false;
  	this.isNS    = false;
  	this.version = null;

  	ua = navigator.userAgent;

  	s = "MSIE";
  	if ((i = ua.indexOf(s)) >= 0) {
    	this.isIE = true;
    	this.version = parseFloat(ua.substr(i + s.length));
    	return;
  	}

  	s = "Netscape6/";
  	if ((i = ua.indexOf(s)) >= 0) {
    	this.isNS = true;
    	this.version = parseFloat(ua.substr(i + s.length));
    	return;
  	}

  	// Treat any other "Gecko" browser as NS 6.1.

  	s = "Gecko";
  	if ((i = ua.indexOf(s)) >= 0) {
    	this.isNS = true;
    	this.version = 6.1;
    	return;
  	}
}


var browser = new Browser();

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


function dragStart(event, id) {

	var el;
  	var x, y;

  	// If an element id was given, find it. Otherwise use the element being
  	// clicked on.

  	if (id)
    	dragObj.elNode = document.getElementById(id);
  	else {
    	if (browser.isIE)
      		dragObj.elNode = window.event.srcElement;
    	if (browser.isNS)
      		dragObj.elNode = event.target;

    	// If this is a text node, use its parent element.

    	if (dragObj.elNode.nodeType == 3)
      		dragObj.elNode = dragObj.elNode.parentNode;					
  	}
		
  
  	// Get cursor position with respect to the page.
  	if (browser.isIE) {
    	x = window.event.clientX + document.documentElement.scrollLeft
      		+ document.body.scrollLeft;
    	y = window.event.clientY + document.documentElement.scrollTop
      		+ document.body.scrollTop;
  	}
	
  	if (browser.isNS) {
    	x = event.clientX + window.scrollX;
    	y = event.clientY + window.scrollY;
  	}
  
  
  	// Save starting positions of cursor and element.

	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 = 0;
  	if (isNaN(dragObj.elStartTop))  dragObj.elStartTop  = 0;
  
  	// Update element's z-index.

  	dragObj.elNode.style.zIndex = ++dragObj.zIndex;
  
  	// Capture mousemove and mouseup events on the page.

  	if (browser.isIE) {
    	document.attachEvent("onmousemove", dragGo);
    	document.attachEvent("onmouseup",   dragStop);
    	window.event.cancelBubble = true;
    	window.event.returnValue = false;
  	}
  	if (browser.isNS) {
    	document.addEventListener("mousemove", dragGo,   true);
    	document.addEventListener("mouseup",   dragStop, true);
    	//event.preventDefault();  ##### cj		
  	}
  
}


  
function dragGo(event) {

  	var x, y;
	
  	// Get cursor position with respect to the page.

  	if (browser.isIE) {
    	x = window.event.clientX + document.documentElement.scrollLeft
      		+ document.body.scrollLeft;
    	y = window.event.clientY + document.documentElement.scrollTop
      		+ document.body.scrollTop;
  	}
  	if (browser.isNS) {
    	x = event.clientX + window.scrollX;
    	y = event.clientY + window.scrollY;		
  	}
  
	// Move drag element by the same amount the cursor has moved.

	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;
  	}
  	if (browser.isNS) {
    	//event.preventDefault(); ##### cj
	}		
	
}
	
	
	
function dragStop(event) {

  	// Stop capturing mousemove and mouseup events.

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