Source code of observer pattern

Problem:
Suppose there are some companies like IBM, Microsoft, Apple etc. These companies have their share price. There are some investors like Suzan, Sharif, Iqbal. They are interested about the share prices of the companies. The investors can register to the companies if they are interested to the share price of a specific company. The investors can unregister if they don’t feel interested any more to a specific company.
When the share price of a company changes, the registered investors are automatically informed about the changed price.

Write a code that shows the above features.

Solve:
Sir already explained enough about the problem domain and what is observer pattern. So here Im here going to give the source only that I have compiled in my machine.

so [You must be registered and logged in to see this link.] it goes.

Cheers!

good work.
RPP.

I have also done this. Erm... with a little bit different approach.
Shall I give the link here?

why not?

Here is my version of the observer pattern implementation.
it is not exactly according to the problem as described in class, I have modified it here and there.

You can view it from [You must be registered and logged in to see this link.]

Bazlu your link is giving problem...please look into it.

I think, my link is doing good ...