How to obtain the value of a DataSourceEnumField

Hi, well my issue is this. I have a DataSourceEnumField and what I want to know is how I can set the display and the value of the enumField.

I am using XJSONDataSource because I am using jsonp to retrieve data.

This is how I have it.

DataSourceEnumField username = new DataSourceEnumField(“user”,“User Name”);

username.setValueXPath(“User/name”);

With this the value is displayed on the field but what I want to obtain is the “User/id”, because what I save in the database is the id not the name.