<!--
function off(num,sub){
   eval("document.img"+num+"_"+sub+".src = img"+num+"_"+sub+"off.src;");
}

function on(num,sub){
   eval("document.img"+ num +"_"+sub+".src = img"+ num +"_"+sub+"on.src");
}

function swap(num,sub){
   eval("img" + num + "_" + sub + "off.src = img" + num + "_" + sub + "on.src;");
}
-->