function navRollOver(imName,over) {
  if (!document.images) {
   return
  }
  
  whichIm = document.images[imName];
  
  if (over==1) {
   whichIm.src = "images/" + imName + "_roll.gif"
  } else if (over==0){
   whichIm.src = "images/" + imName + "" + ".gif"
  } else if (over==2){
  	whichIm.src = "images/" + imName + "_sel.gif"
  }
  
 }
 
 function preloadImg(path,aImg){
 	for(var i=0;i<aImg.length;i++){
		newImage(path + aImg[i])
	}
 }
 
 function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}