function swap () { // v1.0
  var argv = swap.arguments;
  img = (argv.length>0) ? 'img'+argv[0] : null;
  var onoff = (argv.length>1) ? 'on' : 'off';
  document.images[img].src = pix[img][onoff].src;
  if(onoff=='on') return pix[img].status; else return '';
}

function pic () { // v1.0
  var argv = pic.arguments;
  this.off = new Image(); this.off.src = (argv.length > 0) ? 'lib/jpg/'+argv[0] : null;
  this.on  = new Image(); this.on.src  = (argv.length > 1) ? 'lib/jpg/'+argv[1] : null;
  this.status = (argv.length > 2) ? argv[2] : null;
}

pix = new Object();
//for(var i=1;i<10;i++) pix['img'+i] = new pic(i);
pix['img1'] = new pic('cell2.jpg','swap2.jpg');
pix['img2'] = new pic('cell4.jpg','swap4.jpg');
pix['img3'] = new pic('cell9.jpg','swap9.jpg');
pix['img4'] = new pic('cell10.jpg','swap10.jpg');
pix['img5'] = new pic('cell12.jpg','swap12.jpg');