JQ set the default value of the select option, and select set select item;

    <div class="form_class">    
            <select name="test">
                <option value="0">请选择</option>
                <option value="1">订单</option>
                <option value="2">商品</option>
            </select>
        </div>

1, obtaining the value of the selected item value
$ ( "form_class select [name =       'test'].") Val ().;

2, select own designated below Option
$ ( "select form_class [name = 'Test'].") Val (1); \\ 0:. Please select 1: Order 2: Product