function ajaxUpdate(script,update,params,method,indicator){
  if(update){
    new Request({
      url:        script,
      method:     method,
      onRequest: function(request){
         if(indicator){
            $(indicator).setStyle('display','');
         }
      },
      evalScripts:  true,
      onComplete:   function(request){
         if(indicator)
            $(indicator).setStyle('display','none');
      },
      onSuccess:  
         function(response) {
		        $(update).set('html', response);
		     }
    }).send(params);
  }
}

function doAjax(url,target,indicator){
  var ajax = new Ajax(
   url, {
      method: 'get', 
      update: target,
      onRequest : function(){
         if($(indicator)){
            $(indicator).style.display = 'block';
         }
      }
   }).request();
}