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();

// Global object to hold drag information.

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.

// POH 2.4.2009 Kommentoitu
// 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();
}
}

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();
}

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);
}
}

// function showdeadcenterdiv(Xwidth,Yheight,divid) { 
function showdeadcenterdiv(divid) { 

   // First, determine how much the visitor has scrolled 
   
   var scrolledX, scrolledY; 
   if( self.pageYOffset ) { 
      scrolledX = self.pageXOffset; 
      scrolledY = self.pageYOffset; 
   } else if( document.documentElement && document.documentElement.scrollTop ) { 
      scrolledX = document.documentElement.scrollLeft; 
      scrolledY = document.documentElement.scrollTop; 
   } else if( document.body ) { 
      scrolledX = document.body.scrollLeft; 
      scrolledY = document.body.scrollTop; 
   } 

   // Next, determine the coordinates of the center of browser's window 
   
   var centerX, centerY; 
   if( self.innerHeight ) { 
      centerX = self.innerWidth; 
      centerY = self.innerHeight; 
   } else if( document.documentElement && document.documentElement.clientHeight ) { 
      centerX = document.documentElement.clientWidth; 
      centerY = document.documentElement.clientHeight; 
   } else if( document.body ) { 
      centerX = document.body.clientWidth; 
      centerY = document.body.clientHeight; 
   } 

   // The initial width and height of the div can be set in the 
   // style sheet with display:none; divid is passed as an argument to // the function 
   var o=document.getElementById(divid); 
   
   var Xwidth = o.clientWidth;
   var Yheight = o.clientHeight;

   // Xwidth is the width of the div, Yheight is the height of the 
   // div passed as arguments to the function: 
   var leftOffset = scrolledX + (centerX - Xwidth) / 2; 
   var topOffset = scrolledY + (centerY - Yheight) / 2; 

   // The initial width and height of the div can be set in the 
   // style sheet with display:none; divid is passed as an argument to // the function 
   var o=document.getElementById(divid); 
   var r=o.style;

   if (topOffset<1) topOffset = 1;
    
   r.position='absolute'; 
   r.top = topOffset + 'px'; 
   r.left = leftOffset + 'px'; 
   r.display = "block"; 
   
}