// creates select HTML from a name string and an array of options
   function toSelect(name, options) {
                str = "<select name=\"" + name + "\" onchange=\"document.enciclopedia.submit();\">\n<option value=\"\" SELECTED>--Seleziona--</option>\n";
                var n = options.length;
                for (i=0; i<n; i++) {
                        value = options[i];
                        str += "<option value=\"" + value + "\">" + options[i] + "</option>\n";
                }
                str += "</select>\n";
                return str;
   }
   
   function getSecond(value) {
    var url = 'include/sublist.php';
    var myAjax = new Ajax.Request
      (
        url,
        {
          method: "post",
          parameters : "first="+value,           
          onSuccess: function transResult (response) {
                      // split the response text on the delimiter to create an array
                      options = response.responseText.split("|");
                      document.getElementById('sublist').innerHTML = toSelect("second", options);                       
          },
          onFailure: function transResult (response) {
            alert ('Failure'+response.responseText);
          }
        }
      );
      return false;
  }