I have a log file which needs to be checked every 15mins for error.
If the number of error is more than 5 times in given 15mins it should alert.

What have you got so far for a script and what part of it isn't working? Copy and paste it in here and show us what isn't working. It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.***William Henley***
Curt is right; you'll probably get more help if you post code and an example of your log with a spec with more details. This link is an example on how you might cycle thru a file:
http://www.computing.net/answers/un...
