(function($){
  // очищаем select
  $.fn.clearSelect = function() {
    return this.each(function(){
      if(this.tagName=='SELECT') {
        this.options.length = 0;
        $(this).attr('disabled','disabled');
      }
    });
  }
  // заполняем select
  $.fn.fillSelect = function(dataArray) {
    return this.clearSelect().each(function(){
      if(this.tagName=='SELECT') {
        var currentSelect = this;
        $.each(dataArray,function(index,data){
         var option = new Option(data.text,data.value); 	
				if($.browser.msie) {
					currentSelect.add(option);
				  } else {
				  	currentSelect.add(option,null);
				  }
			
        });
      }
    });
  }
})(jQuery);


$(document).ready(function(){
	
// выбор автомобиля
function adjustAuto(){
  var markaValue = $('#marka').val();
  var tmpSelect = $('#model');
  if(markaValue.length == 0) {
    tmpSelect.attr('disabled','disabled');
    tmpSelect.clearSelect();
  } else {
  	
    $.getJSON(
      'ajax.php',
      {marks:markaValue},
      function(data) {
        tmpSelect.fillSelect(data).attr('disabled','');
        //alert(data);
    });
  }
  
};

// выбор автомобиля
function adjustZakaz(){
  var markaValue = $('#coremarks').val();
  var tmpSelect = $('#coremodels');
  if(markaValue.length == 0) {
    tmpSelect.attr('disabled','disabled');
    tmpSelect.clearSelect();
  } else {
  	
    $.getJSON(
      'ajax.php',
      {marks:markaValue},
      function(data) {
        tmpSelect.fillSelect(data).attr('disabled','');
        //alert(data);
    });
  }
  
};

function adjustEng(){
  var modelValue = $('#model').val();
  var tmpSelect = $('#engin');
  if(modelValue.length == 0) {
    tmpSelect.attr('disabled','disabled');
    tmpSelect.clearSelect();
  } else {
  	
    $.getJSON(
      'ajax.php',
      {model:modelValue},
      function(data) {
        tmpSelect.fillSelect(data).attr('disabled','');
        //alert(data);
    });
  }
  
};

function adjustKm(){
  var modelValue = $('#engin').val();
  var tmpSelect = $('#km');
  if(modelValue.length == 0) {
    tmpSelect.attr('disabled','disabled');
    tmpSelect.clearSelect();
  } else {
  	
    $.getJSON(
      'ajax.php',
      {engin:modelValue},
      function(data) {
        tmpSelect.fillSelect(data).attr('disabled','');
        //alert(data);
    });
  }
  
};

  $('#marka').change(function(){adjustAuto();});
  $('#model').change(function(){adjustEng();});
  $('#engin').change(function(){adjustKm();});
  
   $('#coremarks').change(function(){adjustZakaz();});
  
});