InfoPath Dev

I have problem with approval workflow. I created simple form which send form to user for approval. I sent form as attachment to user for approval I am able to send form over email data connection to approval. User able to approve the form. Approved form is successfully submitted to sharepoint Library. My problem is User able to open that email and able to approve over and over. Is there any way we can restrict user to approve only once.

Hmmmm. Maybe promote a field indicating if the form is approved.... and query the library on form load to find out if the current form the user has just opened is approved? I know we can add a data connection to a form library and indicate that we want data for this form only - so perhaps try that option first and see what happens. Otherwise you could promote / store some unique id in the form you could use for the query to get back info for just this form.

Thanks For suggestion. I will try to implement that. I will keep you updated on progress.