Question details:

Can you give me tutorial in Foxpro about this?

Answer:

'Structured programming can be seen as a subset or subdiscipline of procedural programming, one of the major programming paradigms. It is most famous for removing or reducing reliance on the GOTO statement.' More...

'Modularity is a concept that has applications in the contexts of computer science, particularly programming, as well as cognitive science in investigating the structure of mind. A module can be defined variously, but generally must be a component of a larger system, and operate within that system independently from the operations of the other components.' More...

You can find here information about modular programming in FoxPro and here about structured programing.