var popup_dragging = false;
var popup_target;
var popup_mouseX;
var popup_mouseY;
var popup_mouseposX;
var popup_mouseposY;
var popup_oldfunction;


function popup_mousedown(e)
{
  var ie = navigator.appName == "Microsoft Internet Explorer";

  popup_mouseposX = ie ? window.event.clientX : e.clientX;
  popup_mouseposY = ie ? window.event.clientY : e.clientY;
}

function popup_mousedown_window(e)
{
  var ie = navigator.appName == "Microsoft Internet Explorer";

  if ( ie && window.event.button != 1) return;
  if (!ie && e.button            != 0) return;

  popup_dragging = true;
  popup_target   = this['target'];
  popup_mouseX   = ie ? window.event.clientX : e.clientX;
  popup_mouseY   = ie ? window.event.clientY : e.clientY;

  if (ie)
       popup_oldfunction = document.onselectstart;
  else popup_oldfunction = document.onmousedown;

  if (ie)
       document.onselectstart = new Function("return false;");
  else document.onmousedown   = new Function("return false;");
}


function popup_mousemove(e)
{
  var ie      = navigator.appName == "Microsoft Internet Explorer";
  var element = document.getElementById(popup_target);
  var mouseX  = ie ? window.event.clientX : e.clientX;
  var mouseY  = ie ? window.event.clientY : e.clientY;

  if (!popup_dragging) return;

  element.style.left = (element.offsetLeft+mouseX-popup_mouseX)+'px';
  element.style.top  = (element.offsetTop +mouseY-popup_mouseY)+'px';

  popup_mouseX = ie ? window.event.clientX : e.clientX;
  popup_mouseY = ie ? window.event.clientY : e.clientY;
}


function popup_mouseup(e)
{
  var ie      = navigator.appName == "Microsoft Internet Explorer";
  var element = document.getElementById(popup_target);

  if (!popup_dragging) return;

  popup_dragging = false;

  if (ie)
       document.onselectstart = popup_oldfunction;
  else document.onmousedown   = popup_oldfunction;
}


function popup_exit(e)
{
  var ie      = navigator.appName == "Microsoft Internet Explorer";
  var element = document.getElementById(popup_target);

  popup_mouseup(e);
  element.style.display = 'none';
}


function popup_show(id, drag_id, exit_id, image_id)
{
  var element      = document.getElementById(id);
  var drag_element = document.getElementById(drag_id);
  var exit_element = document.getElementById(exit_id);
  var theImg 	   = document.getElementById(image_id);

  if (window.innerWidth) //if browser supports window.innerWidth
  {
	  width = window.innerWidth;
      height = window.innerHeight;
  }
  else
  {
	  width = document.body.offsetWidth;
      height = document.body.offsetHeight;
  }
  element.style.position = "absolute";
  element.style.display  = "block";

  var iebody=(document.compatMode && document.compatMode != "BackCompat")? document.documentElement : document.body
  var dsocleft=document.all? iebody.scrollLeft : pageXOffset
  var dsoctop=document.all? iebody.scrollTop : pageYOffset

  element.style.left = (dsocleft+(width-theImg.width)/2)+'px';
  if ((dsoctop+(height-theImg.height)/2) > 150)
	  element.style.top = ((dsoctop+(height-theImg.height)/2)-150)+'px';	
  else
	  element.style.top = (dsoctop+(height-theImg.height)/2)+'px';	
  
  drag_element.style.width = theImg.width;  
  drag_element['target'] = id;
  drag_element.onmousedown = popup_mousedown_window;
  exit_element.onclick = popup_exit;
}


if (navigator.appName == "Microsoft Internet Explorer")
     document.attachEvent   ('onmousedown', popup_mousedown);
else document.addEventListener('mousedown', popup_mousedown, false);

if (navigator.appName == "Microsoft Internet Explorer")
     document.attachEvent   ('onmousemove', popup_mousemove);
else document.addEventListener('mousemove', popup_mousemove, false);

if (navigator.appName == "Microsoft Internet Explorer")
     document.attachEvent   ('onmouseup', popup_mouseup);
else document.addEventListener('mouseup', popup_mouseup, false);