Thread: hi need help with inheritance

hi i m a beginner creating a national database program for practice.

i have 5 packages in my program each having 1 class

1. general (class gen)
class gen contains basic info like name age etc.

2. nii ( class nii)
this class contains identity information like nicno, mark of identification etc

3. medical (class medical)
this information contains the medical info like diseases, treatments etc.

4. insurance (class insure)
this class contains insurance info like insurance id, accidents etc.

5. joint (class national)
this class contains all the information of a person. gen+nii+health+medical

now i want to extend medical with nii and nii with gen + insure with nii, and nii with general

then i want to inherit all the classes variables above in nationals.

so that only nationals have all the information, insure have only insrance + general+ nii information and
medical have their information and medical and insurance cant share information with eachother..

can any one help me please how i can do this??

i thought may be i could get answer fast. or i can get more replies and learn more -_-.