Safari not working properly

Hi! I am using white polycarbonate MacBook 13" Mid 2010 with Mac OS X Lion 10.7.5.

Whenever I am opening Safari (Version 6.1.6), the message comes "you are not connected to internet" for the last one week. Tried in System preferences

and found the connectivity is o.k. & reset Safari . Then, also, the same problem; not able to open any website.

I tried browsing through Google Chrome & Firefox. They work perfectly. Incidentally, this question is posted using Google Chrome.

I am using Safari for more than 8 years in both my iMac and Mac Book and got used to it. Any suggestions how to rectify Safari?

Thanks in advance

J.SRIDHARAN