Keep spreading your magic: B-Town on SRK's 50th birthday

To some, he's been an inspiration; to some, he's like family. Superstar Shah Rukh Khan has been described as the "biggest star with the biggest heart" by the Hindi film fraternity, who have wished the 'king of romance' good health, more success and happiness on his 50th birthday on Monday.

A host of actors like Hrithik Roshan and Preity Zinta and filmmakers like Karan Johar and Anubhav Sinha took to Twitter to share their birthday wishes for SRK, who hopes to have a quiet celebration with his family members.

The "Dilwale" star gave his admirers a treat by launching a new teaser of "Fan", in which he plays a man named Gaurav, who is a fan of Shah Rukh Khan, the superstar.

Here's what the celebrities had to say:

Karan Johar: A big reason for my beginning as a filmmaker. I will always be grateful... Happy 50 Bhai!!! Your golden era is legendary... Big love @iamsrk

Boman Irani: Not seen a slip in his spritely step nor his mental ticker and fatigue is for those who try to keep up with him. 50? Ok! Happy birthday @iamsrk

Sajid Khan: Indian cinema has turned 104... and its king of hearts has turned 50...happy bday @iamsrk.

Hrithik Roshan: Happy birthday @iamsrk may all your FANS have a great day today. Applause for your vision and all at Red Chillies! Loved it.

Sophie Choudry: Happy birthday to the most inspiring, energetic, king of awesomeness @iamsrk. 50 is now cooler than ever because it's got you in the club! #SRKat50

Sonu Sood: I always wished I had an elder brother, then I met Shah... yes wishes do come true. Happy birthday @iamsrk love you the most.

Farhan Akhtar: Happy Birthday to you, happy birthday to you, happy birthday dear Don, happy.

Sonu Nigam: Happy Birthday to you my dear brother @iamsrk... God bless you with the health and ability to brighten the lives of your fans. Prayers.

Kriti Sanon: Happiest birthday @iamsrk sir! Youngest and the most energetic 50-year-old ever! Keep inspiring us as always sir! Waiting to celebrate in Goa!

Vishal Dadlani: Happy birthday to the one and only @iamsrk! "Dilwale" is going to be the biggest film in many years, and may the successes keep on coming!

Ronnie Screwvala: @iamsrk have a stupendous year ahead - success - You are the best example for millions to dream big and with your eyes open - stay that way!

Preity Zinta: Happy birthday @iamsrk! Loads of love, luck, sexiness, health and blockbusters to my first hero and to the man I truly admire and love.

Gurinder Chadha: Happy birthday to the loveliest man in Mumbai so happy to be with you on the awesome day @iamsrk

Anupam Kher: Happy Birthday to the most charming, affectionate and infectious @iamsrk. Love, peace and happiness always.

Ayushmann Khurrana: He's the reason I dreamt of becoming an actor. He's the reason I studied mass communication. He's the reason I believe in love. Happy birthday @iamsrk sir.

Anubhav Sinha: Happy Happy Shah Rukh. Keep smiling. Keep inspiring. Keep redefining Success. Wish you all the happiness! @iamsrk Welcome to the club!

Huma Qureshi: Happy birthday @iamsrk The superstar and the most charming man I have ever met... lots of love. Wishing you love, luck, health and happiness always.

Genelia Deshmukhd: May you put smiles on faces for a billion years, just like you always put on mine. Happy Birthday @iamsrk

Ranganathan Madhavan: @iamsrk Wish you a very happy birthday and a wonderful long life that continues to magically entertain all your fans.

Sanjay Gupta: We started at the same time in the lobby of Sippy Films. What a journey! Happy birthday @iamsrk! Keep on conquering Shah.

Sushant Singh Rajput: Happy birthday to the one of the most....naam hi Kaafi he @iamsrk!! From one of the million #gaurav like #fan. #HappyBirthdayKingKhan

Vivek Oberoi: Wishing @iamsrk a very happy 50th birthday! The euphoria today shows exactly why he is and always will be the King Khan of Indian cinema!!!