如何在Tapestry4.2中使用单选按钮？

Question

这部分我在.html中添加：

<form jwcid="@Form" success="listener:doSubmit">
  <span jwcid="acknowledge@RadioGroup" selected="ognl:acknowledgeUser" displayName="user">
    <input type="radio" jwcid="@Radio" value="ognl:@com.simpragma.pages.Home@YES" />YES
    <input type="radio" jwcid="@Radio" value="ognl:@com.simpragma.pages.Home@NO" />NO  
  </span>
</form>                                                                                                   

这是我在Java中添加的：

public final static boolean YES=true;
public final static boolean NO=false;

public abstract boolean getAcknowledgeUser();

这是我在.page文件中添加的：

<page-specification class="com.simpragma.pages.Home">
    <property-specification name="acknowledgeUser" type="boolean" />
</page-specification>