burl="http://adserver.ad-space.net/images/";
bext=".gif";
ion="";
ioff="2";
idown="3";

function preloadImage(name){
var n=sr(name);
 eval (n+"_on = new Image()");
 eval (n+"_on.src='"+burl+name+ion+bext+"'");
 eval (n+"_off =new Image()");
 eval (n+"_off.src='"+burl+name+ioff+bext+"'");
 eval (n+"_down = new Image()");
 eval (n+"_down.src='"+burl+name+idown+bext+"'");
}

function sr(i){ //replace wrong char in var names
 return i.replace('-','_');
}

function preloadImages(){
var i,a=preloadImages.arguments;
 if (document.images){ 
  for(i=0; i<a.length; i++){ 
   preloadImage(a[i]);
 }
 }
}

function imgOn(imgName) {
var imgNamer=sr(imgName);
if (document.images) {
 document[imgName].src=eval (imgNamer +"_on.src");
}
}

function imgOff(imgName) {
var imgNamer=sr(imgName);
if (document.images) {
 document[imgName].src=eval (imgNamer +"_off.src");
}

}

function imgDown(imgName) {
var imgNamer=sr(imgName);
if (document.images) {
 document[imgName].src=eval (sr(imgNamer) + "_down.src");
}
}