Shahid,
You have to ensure that you are running the appropriate version of IOS on your device - one that supports IPS. You can be sure by using our Feature Navigator:
http://tools.cisco.com/ITDIT/CFN/
If your IOS does support IPS, you can reference the link below on configuration guidance as a starting point:
IPS 5.x:
http://www.cisco.com/en/US/prod/collateral/iosswrel/ps6537/ps6586/ps6634/prod_white_paper0900aecd805c4ea8.html
Depending on whether you are going to be using IPS 4.x or 5.x, this process will vary.
Let me know if this addresses your question. If it does, please be sure to mark this question as answered!
Best Regards,
Kevin