function newImage(arg) {
 rslt = new Image();
 rslt.src = arg;
 return rslt;
}

function grokObj(myObj,myDoc) {
  var i,x;
  if(!myDoc) myDoc=document;
  if(!(x=myDoc[myObj])&&myDoc.all) x=myDoc.all[myObj];
  for (i=0;!x&&i<myDoc.forms.length;i++) x=myDoc.forms[i][myObj];
  for(i=0;!x&&myDoc.layers&&i<myDoc.layers.length;i++) x=grokObj(myObj,myDoc.layers[i].document);
  if(!x && document.getElementById) x=document.getElementById(myObj);
  return x;
}

function swapoff(whichImg) {
  var vms=grokObj(whichImg);
  eval('vms.src = '+whichImg+'off.src');
}

function swapon(whichImg) {
  var vms=grokObj(whichImg);
  eval('vms.src = '+whichImg+'on.src');
}

previouson=newImage('images/previous2.gif');
previousoff=newImage('images/previous1.gif');

nexton=newImage('images/next2.gif');
nextoff=newImage('images/next1.gif');