I am not exactly sure what you are doing with JavaScript, but maybe this will help. When you submit your page all the form fields on your page are posted on the request. If you have your forms configured to use request scope,
Struts creates a brand new instance of your form and populates it with the values on the request. If validation fails your page is regenerated with just the values that are currently in your form. It might be that you need to populate hidden fields or that you need to execute some JavaScript code when your page is loaded.
- Brent