$(document).ready(function(){

  // выбор артиста
  function adjustArtist(){
  	var letterValue = $('#letter').val();
  	var tmpSelect = $('#id_artist');
  	if(letterValue.length == 0) {
  		tmpSelect.attr('disabled','disabled');
  		tmpSelect.clearSelect();
  		adjustsong();
  	} else {
  		$.getJSON('cascadeSelectArtist.php',{letter:letterValue},function(data) { tmpSelect.fillSelect(data).attr('disabled',''); adjustsong(); });
  		
  	}
  };
  // выбор песни
  function adjustsong(){
  	var letterValue = $('#letter').val();
  	var artistValue = $('#id_artist').val();
  	var tmpSelect = $('#song');
  	if(letterValue.length == 0||artistValue.length == 0) {
  		tmpSelect.attr('disabled','disabled');
  		tmpSelect.clearSelect();
  	} else {
  		$.getJSON('cascadeSelectSong.php',{letter:letterValue,id_artist:artistValue},function(data) { tmpSelect.fillSelect(data).attr('disabled',''); });
  	}
  };
	
  $('#letter').change(function(){
  	adjustArtist();
  }).change();
  $('#id_artist').change(adjustsong);
  $('#song').change(function(){
  	if($(this).val().length != 0) { window.location.href = 'translations.php?id_translation=' + $(this).val(); }
  });

});