Hello miguelsneto,

I prepared a sample for your scenario and attached it to this post.

If the button which says "Validate!" on my form is visible, the text boxes in 'groupBox2' are required, if it is hidden then the text boxes in the first group box are required. If a text box which is required is not valid, the form could not be closed.

I am validating only on value changed in the optionSet(which is used to show and hide the button) and on clicking the ultraButton control. So these are the options to validate the form.

Please feel free to let me know if I misunderstood you. I also will be glad to assist you if you have any other questions.