InfoPath Dev

Hello ,

i have a probleme with a dropdown list to controle a repeating section(the last contains repeating table)

the data structure are:

Projects

--Project(repeating)

------ ProjectId

------ ProjectName

------SubProject(repeating)

------ ---SubProjectId

------ ---SubProjectName

------ ---Employees(repeating)

------ ------EmployeeName

------ ---Materiels(repeating)

------ -----MaterielsQuantite

i have 2 xml files containe Projects (Id and name) and subProject (Id and name)

what i want to do is to use tow dropdown list to disply a section with related information, so user can fill out the form.

i tried many combination of repeating section binded to external data and inside and i put a repeating table inside but it doesnt work

can somone show me the logical way to do that

Thanks