Categorias Mercado Livre

gistfile1.html

<script src="http://code.jquery.com/jquery-1.10.2.min.js"></script>

<script>
	$(function(){
		$.get('https://api.mercadolibre.com/sites/MLB/categories', function(categories){
			for (var i in categories) {
				$('#categories').append('<option value="'+categories[i].id+'">'+categories[i].name+'</option>');
			}
		});
	});

	function getSubCategories(id){
		$('#subCategories option').remove();
		$('#subCategories').append('<option id="loading">Carregando...</option>');
		$.get('https://api.mercadolibre.com/categories/'+id, function(data){
			subCategories = data.children_categories;
			for (var i in subCategories) {
				$('#subCategories').append('<option value="'+subCategories[i].id+'">'+subCategories[i].name+'</option>');
			}
			$('#subCategories #loading').remove();
		});
	}
</script>

<select id="categories" onChange="getSubCategories(this.value)">
	<option>Selecione a categoria</option>
</select>

<select id="subCategories"></select>

The best of the world. I love you XD