function $(id) {
    return document.getElementById(id);
}


function trim(sString) {
   while (sString.substring(0,1) == ' ') {
      sString = sString.substring(1, sString.length);
   }

   while (sString.substring(sString.length-1, sString.length) == ' ') {
      sString = sString.substring(0,sString.length-1);
   }

   return sString;
}



function changeContent(id_content, id_article) {

  advAJAX.post({

      url: "ajax.php",
      parameters : {
        "id" : id_content,
        "id_article" : id_article
      },

      onInitialization : function(obj) {
         $("loading").style.display = "block";
         if(id_content==null) {
            alert('devi selezionare qualcosa');
            obj.aborted = true;
         }
      },

      onSuccess : function(obj) {
         $("loading").style.display = "none";
         $("main").innerHTML = obj.responseText;
      },

      onError : function(obj) {
         if( obj.status == 404 ) {
            alert("La pagina di ricerca non e' al momento disponibile");
         }else {
            alert("Ci sono dei problemi - " + obj.readyState + " - " + obj.status);
         }
      }

  });

}