function preload(imgObj,imgSrc) {
eval(imgObj+'on = new Image()')
eval(imgObj+'on.src = "'+imgSrc+'on.jpg"')
eval(imgObj+'off = new Image()')
eval(imgObj+'off.src = "'+imgSrc+'off.jpg"')
}

function preload2(imgObj,imgSrc) {
eval(imgObj+'on = new Image()')
eval(imgObj+'on.src = "'+imgSrc+'.jpg"')
}

function img_act(imgName, act)  {
   imgOn = eval(act + "on.src");
   document [imgName].src = imgOn;

}

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

preload('lands','/gallery/images/lands_')
preload('aviat','/gallery/images/aviat_')
preload('birds','/gallery/images/birds_')
preload('buy','/gallery/images/buy_')
preload('info','/gallery/images/info_')
preload('close','/gallery/images/close_')