6.4 变量设置元素与变量设置的有关规定

                            </do>

                            <do type="accept" label="Third Card">

                                     <go href="#card3">

                                               <setvar name="card2_var1" value="val_2"/>

                                     </go>

                            </do>

                            <do type="prev" label="Previous Card">

                                     <prev/></do>