Sharepoint 2010 Alerts on Discussion Board

Hi,

I Have created a discussion Board and My requirement is as follows :-

• Discussion Forum: Anyone who is a part of a discussion should receive an automatic email alert for modification, addition, deletion – any changes in the discussion
• I Have used OOB Alert but since my requirement is that it should fire the Alert for only those person who are in the part of discussion which leads me to think how can i proceed with these.

Please Help me if anyone has worked on these

Thanks ,

Simanchal