Casting exception during form validation of nested:select (Struts 1.3.10) - struts

Question

I am now trying to dig into struts framework and now, I am testing nested-tags. I encounter problem when I retrieve data. My code is as following :
<nested:select property="formatDisponible">
<logic:iterate id="listFormat" property="formatList" name="videoGameForm">
<html:option value="${listFormat}" />
</logic:iterate>
</nested:select>
When I perform validation action (by that I mean retrieving data from my form) I got the following exception:
GRAVE: Method invocation failed.
java.lang.IllegalArgumentException: java.lang.ClassCastException#110e3b5
at sun.reflect.GeneratedMethodAccessor80.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
Thank you for your help (I will update you about any change).
I finally found what was going wrong in my previous code. If somehow, other people are facing the same problem, I am going to put the correct code below.
<nested:nest property="formatDisponible">
<nested:select property="id">
<html:options collection="formatList" property="id" labelProperty="nom" labelName="id"></html:options>
</nested:select>
</nested:nest>
I corrected my first test and ended up with that solution. The only thing I am trying to figure out right now is how to set selected value (because I am using this form to update my object). If I can resolve it, I will update my post.

Answer 1

All my problem related to this question was solved (at least for now). I accidentally overloaded the value of the select property.