/> Rishi Kapoor can't stop smiling. His son Ranbir's "Wake Up Sid" has got an overwhelming response from audiences and critics alike, but Kapoor senior is cautious and says his son will have to continuously prove himself as it is not the surname but one's performance that ultimately counts in the film world.

"Just being a Kapoor was never going to be enough. Ranbir had to show his worth as an actor. I also had Raj Kapoor as father, but it has never been easy for me even till date.

For the last 40-odd years, I have been proving myself. The same would always hold good for Ranbir. It's a never-ending journey, " Rishi, who belongs to the third generation of the Kapoor family, told.

At the same time, he is unable to conceal his excitement with the positive reviews and appreciation coming his son's way.

"Ever since Thursday evening, once the preview shows and other private screenings were held, I have been inundated with congratulatory calls. I was humbled and was waiting for audience reactions once the film opened to public viewing on Friday, " Rishi said.

He reveals that he was in constant discussions with wife Neetu Singh, who on her part was sure that the film would strike a chord amongst youth.

"She assured me that the current generation would truly identify with what the film is all about. We both had seen the film and Neetu was quite confident about the setting and milieu of the film. She asked me not to worry at all. She was right, " Rishi said.

Produced by Karan Johar and directed by newcomer Ayan Mukerji, "Wake Up Sid" also stars Konkana Sen Sharma.

The actor says he is proud of the way Ranbir's career has progressed during the last couple of years with first "Saawariya", where he received critical acclaim, then "Bachna Ae Haseeno", which did well at the box office, and now "Wake Up Sid".

"My chest is swollen with pride. As a father, I am so excited that my son has been doing so well in his career. This hasn't been an overnight job by him though. He has worked hard to earn it.

"Star son or no star son, everything just vanishes when the film comes on screen. It's your performance that ultimately speaks, " Rishi said.