function alpha_up(max,start,speed,alpha_obj){
 alpha_obj.style.display="";
 if(start-speed<=max){
  if(isNetscape){
   if(start<=100){
    alpha_obj.style.MozOpacity=start/100;
   }
  }else{
   set_alpha(alpha_obj,start);
  }
  start=start+speed;
  setTimeout("alpha_up("+max+","+start+","+speed+",document.getElementById('"+alpha_obj.id+"'))",50);
 }
}
function alpha_down(max,start,speed,alpha_obj){
 if(max<1&&(start+speed)<=max){
  alpha_obj.style.display="none";
 }
 if(start+speed>max){
  set_alpha(alpha_obj,start);
  start=start-speed;
  setTimeout("alpha_down("+max+","+start+","+speed+",document.getElementById('"+alpha_obj.id+"'))",50);
 }
}
function set_alpha(alpha_obj,alpha){
 alpha_obj.style.KHTMLOpacity=alpha/100;
 alpha_obj.style.MozOpacity=alpha/100;
 alpha_obj.style.opacity=alpha/100;
 if(!isNetscape){
  alpha_obj.filters.alpha.opacity=alpha;
 }
}