warangalboy, please read our rules. And in particular:
(4) Do not 'bump up' questions if they are not answered promptly. No duplicate or cross-posting and do not report a post where your goal is to get an answer more quickly.
Both your duplicate thread and your "Can any plz help" post are against that rule. If this is just a problem from some book and not a classwork assignment, can you help me understand the urgency? What would be your idea of a low priority problem?
vino, the "kill -0 $pid" idea is great. That's a much better way to check if the process is still running. But if those kill commands don't work, the skill commands won't help either. Anyway skill won't be on most unix boxes. I have only seen it on Linux.
Complex signals like this do not mix well with many shell scripts. The problem is that shell scripts are a collection of processes, not the single process that you are signalling.