InfoPath Dev

Hi, My Infopath forms(originally developed in IP 2003 and later enhancements using IP 2007 [backward compatibility]) were published to SP 2007 site. Now we are moving to SP 2010 site and am successfull in publishing all my forms to SP 2010 site. Also am able to fill and submit forms after publishing...

I have a form with a section that must be signed before the user can submit, but once signed if the form is to be completed at a later date the user must be able to edit the section, How can i remove the signature for the section the user must edit?

I need to create a calculated text field based on two other Combo box on the form The problem is that if another selection is made in the Combo box the text field does not change accordingly since its a sharepoint list form i cant use code behind and because there is no such thing as an if statement...