function checkTrackSearchForm() {
  var obj = document.forms[0];  

  if(obj.mainArtist.value == "" &&
 //  obj.composer.value  == "" &&
   obj.title.value  == "") {
     alert("NESSUN CRITERIO DI SELEZIONE!\nOccorre usare almeno un criterio di selezione\nnei campi Titolo, Interprete o Autore");
     obj.title.focus();

     return false;
  } 

  if(((obj.mainArtist.value.length > 0) && (obj.mainArtist.value.length < 4)) ||
    // ((obj.composer.value.length > 0) && (obj.composer.value.length < 4))     ||
     ((obj.title.value.length > 0) && (obj.title.value.length < 4))) {
      var an = confirm("One of the search criteria has less than 4 characters !\nTherefore it could take a while to find the tracks.\nDo you really want to continue?");
      if (an == false)
        return false;
  }
       

  return true;
}