Form validation

Hello,

I am using FormWizard with a 12-step form.

On step 6, I want to perform verification on a field but it depends on fields that were entered in steps 2-5.

I cannot figure out how to get data from the previous steps in the form validation for step 6.

Where is a point in the FormWizard where I can access previous form data and can also raise ValidationError on a field?

Thanks,