function newImage( imgSrc ){

 var imgName = new Image();
 imgName.src = imgSrc;

 return imgName;

}

function change( imgName, imgLocation )
{
 document[imgName].src = imgLocation ;
}

var preloadFlag = false;
function loadImages()
{
 if (document.images)
 {

 about_on = newImage("images/AboutOn.jpg");
 markets_on = newImage("images/MarketsOn.jpg");
 services_on = newImage("images/ServicesOn.jpg");
 contact_on = newImage("images/ContactOn.jpg");

 preloadFlag = true;
 }
}

function openPopUp(url)
{
  var width  = 550;
  var height = 400;
  var left   = (screen.width  - width)/2;
  var top    = (screen.height - height)/2;
  var params = 'width='+width+', height='+height;
  params += ', top='+top+', left='+left;
  params += ', directories=no';
  params += ', location=no';
  params += ', menubar=no';
  params += ', resizable=no';
  params += ', scrollbars=no';
  params += ', status=no';
  params += ', toolbar=no';
  newwin=window.open(url,'windowname5', params);
  if (window.focus) {newwin.focus()}
  return false;
}