tb1on = new Image(0,0);
tb1on.src = 'images/1b.gif';
tb1off = new Image(0,0);
tb1off.src = 'images/1a.gif';

tb2on = new Image(0,0);
tb2on.src = 'images/2b.gif';
tb2off = new Image(0,0);
tb2off.src = 'images/2a.gif';

tb3on = new Image(0,0);
tb3on.src = 'images/3b.gif';
tb3off = new Image(0,0);
tb3off.src = 'images/3a.gif';

tb4on = new Image(0,0);
tb4on.src = 'images/4b.gif';
tb4off = new Image(0,0);
tb4off.src = 'images/4a.gif';



tb5on = new Image(0,0);
tb5on.src = 'images/5b.gif';
tb5off = new Image(0,0);
tb5off.src = 'images/5a.gif';

rb1on = new Image(0,0);
rb1on.src = 'images/v1b.gif';
rb1off = new Image(0,0);
rb1off.src = 'images/v1a.gif';

rb2on = new Image(0,0);
rb2on.src = 'images/v2b.gif';
rb2off = new Image(0,0);
rb2off.src = 'images/v2a.gif';

rb3on = new Image(0,0);
rb3on.src = 'images/v3b.gif';
rb3off = new Image(0,0);
rb3off.src = 'images/v3a.gif';

rb4on = new Image(0,0);
rb4on.src = 'images/v4b.gif';
rb4off = new Image(0,0);
rb4off.src = 'images/v4a.gif';

rb5on = new Image(0,0);
rb5on.src = 'images/v5b.gif';
rb5off = new Image(0,0);
rb5off.src = 'images/v5a.gif';

rb6on = new Image(0,0);
rb6on.src = 'images/v6b.gif';
rb6off = new Image(0,0);
rb6off.src = 'images/v6a.gif';

rb7on = new Image(0,0);
rb7on.src = 'images/v7b.gif';
rb7off = new Image(0,0);
rb7off.src = 'images/v7a.gif';

rb8on = new Image(0,0);
rb8on.src = 'images/va8b.gif';
rb8off = new Image(0,0);
rb8off.src = 'images/va8a.gif';

dison = new Image(0,0);
dison.src = 'images/11b.gif';
disoff = new Image(0,0);
disoff.src = 'images/11a.gif';

linkson = new Image(0,0);
linkson.src = 'images/12b.gif';
linksoff = new Image(0,0);
linksoff.src = 'images/12a.gif';

function changeImgOn(imgName){

   imgOn=eval(imgName + "on.src");
    document[imgName].src = imgOn;
}

function changeImgOff(imgName){
  imgOff=eval(imgName + "off.src");
   document[imgName].src = imgOff;
}