InfoPath Dev

 Hi I want to subtract a column and a Value. what am I do?  

Hi I was create a repeating section and drag a combo box within it. in the combo box we have some value for example A,B,C and D i want the user can not ability select same value in one selected. I mean for example Mr.Jon selected aren't A , A or B , B he can select A,C or B,C etc... what am i do?

 Hi I want to create for example Request Shipping form. i was create a form and publish to a SharePoint library.i was set the  Repeating Section for choice commodity and its price. users can select any number commodity. but i have two request: 1- the user do not have ability to select same commodity within a day according to ...