function switchImage(imgName, imgSrc) 
{
  if (document.images)
  {
    if (imgSrc != "none")
    {
      document.images[imgName].src = imgSrc;
    }
  }
}
// JavaScript Document  

var currentSection=null;

function rollover (imgName, imgSrc) {
	
	if(imgName!=currentSection){
	 switchImage(imgName, imgSrc);	
	}

}

function setSection(imgName, imgSrc) {
	currentSection=imgName;
	switchImage(imgName, imgSrc);
}