Onchange function not working using laravel5

Onchange function not working using laravel5.here i select the second category from same table.i can get the first category id.onchange function is the problem.what i need to change. Controller

public function ajax_select_sub_second_cat()
{

     $id =  $_GET['id'];
     $main_cat = Category_model::get_sub_category_ajax($id);
    //return view('siteadmin.add_cat',['main_cat' => $category]);
    if($main_cat)
    {
        $return  = "";
        $return  = "<option value='0'> -- Select -- </option>";
        foreach($main_cat as $main_cat_ajax) {

        $return .= "<option value='".$main_cat_ajax->sub_category1."'> ".$main_cat_ajax->sub_category1." </option>";        
        }
        echo $return;
    }
    else
    {
    echo    $return = "<option value='0'> --Select-- </option>";
    }
}

view

<select id="subcategory" name="product_sub_category" onChange="getCat1(this.value);"> 

-----Select Standard-----

  <script>
  function getCat1(id)
     {
   var passData = 'id='+id;
   $.ajax( {
        type: 'get',
      data: passData,
      url: '<?php echo url('ajax_select_sub_second_cat'); ?>',
      success: function(responseText){  
       if(responseText)
       { 
      $('#subcategory2').html(responseText);            
       }
    }   
  }); 

}

  </script>

via Chebli Mohamed