Validate an hmt:select with validator framework

[Heidy Gutiérrez Guzmán]

Hi

I need to validate an html:select with validator framework

This is the code that i have


<html:select property="categoria" styleClass="editGrande">

<html:option value="null">---</html:option>

<html:options collection="categoriasDescarte" property="id" labelProperty=
"nombre"></html:options>

</html:select>

I need have a default value that is " ---" , but i need validate that this
value does'nt selected.

The code in the Validator form is
private Long categoria;

I tried to use the required validation, but that does'nt work, i think
because the html:select have the "---" default value