if(document.images) {
  var imgRollArray = new Array();
  var imgArray = new Array();

  var imgPath = '/images/';
  
  imgArray["prog_info"]   = new Image();
  imgArray["signup"]      = new Image();
  imgArray["class_desc"]  = new Image();
  imgArray["enrollment"]  = new Image();
  imgArray["suggestions"] = new Image();
      
  imgArray["prog_info"].src = imgPath + "prog_info.jpg";
  imgArray["signup"].src = imgPath + "signup.jpg";
  imgArray["class_desc"].src = imgPath + "class_desc.jpg";
  imgArray["enrollment"].src = imgPath + "enrollment.jpg";
  imgArray["suggestions"].src = imgPath + "suggestions.jpg";
  
  imgRollArray["prog_info"]   = new Image(133,37);
  imgRollArray["signup"]      = new Image(133,37);
  imgRollArray["class_desc"]  = new Image(133,37);
  imgRollArray["enrollment"]  = new Image(133,37);
  imgRollArray["suggestions"] = new Image(133,37);
  
  imgRollArray["prog_info"].src = imgPath + "prog_info_over.jpg";
  imgRollArray["signup"].src = imgPath + "signup_over.jpg";
  imgRollArray["class_desc"].src = imgPath + "class_desc_over.jpg";
  imgRollArray["enrollment"].src = imgPath + "enrollment_over.jpg";
  imgRollArray["suggestions"].src = imgPath + "suggestions_over.jpg";

}

function imgRoll(imgID) {
  if(document.images) document.images[imgID].src = imgRollArray[imgID].src;
} 

function imgOff(imgID) {
  
  if(document.images) document.images[imgID].src = imgArray[imgID].src;
}