problem using validwhen and radio button

[Mona Tajik]

hello all..

can anyone pls help me with my problem here? I'm trying to validate a form using the validwhen in struts. I have a form to add a user which contains a radio button group. Whenever one of the radio button is selected the corresponding textbox should also be filled. I manage to make the validation work but it is now requiring the user to fill up both the radio button and the text box What I wanted is just if one radio button is selected one text box should also be filled.. please help...........
validation.xml

<formset>
    <form name="AddForm">
 <field
        property="txt_1"
        depends="validwhen">
        <arg0 key="error.txt_1"/>
       <var>
<var-name>test</var-name>
<var-value>((radioGroup=="1")and(*this* != null))</var-value>
</var>
  </field>
   <field
        property="txt_2"
        depends="validwhen">
         <arg0 key="error.txt2"/>
<var>
<var-name>test</var-name>
<var-value>((radioGroup=="2")and(*this* != null))</var-value>
</var>
    </field>
</form>

snippet of Add.jsp

<tr>
<td><html:radio property="radioGroup" value="1"/>Radio one</td>
<td><html:text property="txt_1" size="20"/></td>
</tr>
<tr>
  <td><html:radio property="radioGroup" value="2"/>Radio two</td>
         <td><html:text property="txt_2" size="20"/></td>
</tr>