InfoPath Dev

Ok I have tried many times I used the codeless programming from the bizsupport online all it ever returns is 0 for the diffrence. http://www.bizsupportonline.net/infopath2007/calculate-date-difference-infopath-rules-formulas.htm  

I have found some stuff online for this but im not sure I understand it. I want to calculate the number of days between 2 date picker boxes into a third field.

I really dont remember making that change in the other form. But thanks.

This may be a very simple question but I cant find it. When you choose add a rule and then an action not all the actions are showing, there is one where you can make a dialog box appear but its not showing up on a new form I am creating. This action is on another one but it seems to have just appread randomly as selectable. can ...