if (document.images) {
//--Top Navigation
img2ro = new Image();
img2ro.src = "images/rollSPANAbout.gif";
img2norm = new Image();
img2norm.src = "images/btSPANAbout.gif";
img3ro = new Image();
img3ro.src = "images/rollSPANMarket.gif";
img3norm = new Image();
img3norm.src = "images/btSPANMarket.gif";
img4ro = new Image();
img4ro.src = "images/rollSPANServices.gif";
img4norm = new Image();
img4norm.src = "images/btSPANServices.gif";
img5ro = new Image();
img5ro.src = "images/rollSPANPublications.gif";
img5norm = new Image();
img5norm.src = "images/btSPANPublications.gif";
img6ro = new Image();
img6ro.src = "images/rollSPANArticles.gif";
img6norm = new Image();
img6norm.src = "images/btSPANArticles.gif";
}

//--Rollover function
function changeImages(normal, rollover)
{
  if (document.images) 
  {document.images[normal].src = eval(rollover + ".src");
  }
}