Los Angeles, Aug 9 : The late Olivia Newton-John's 'Grease' co-star John 'Danny Zuko' Travolta took to social media to pay his personal tribute to her. "My dearest Olivia, you made all of our lives so much better," Travolta wrote in a post quoted by 'Variety'. "Your impact was incredible. I love you so much. We will see you down the road and we will all be together again. Yours from the moment I saw you and forever! Your Danny, your John!" Newton-John, who was later in the news for her fight against cancer and for being a fitness diva, passed away at her ranch in southern California on Monday at the age of 73. Travolta and Newton-John headlined 'Grease', delivering two of their most iconic film performances as Danny Zuko and Sandy Olsson, respectively. The 1978 musical, directed by Randal Kleiser, became a cultural phenomenon with $366 million at the worldwide box office, according to 'Variety'. The single 'Hopelessly Devoted to You', performed by Newton-John, was nominated at the Oscars for original song. The film's soundtrack was the second biggest album of 1978 in the US, trailing only that of the Travolta-starring 'Saturday Night Fever'. Following the release of 'Grease', Travolta and Newton-John remained lifelong friends. The two often reunited to celebrate the movie. At a 40th-anniversary screening for 'Grease' in 2018, the duo memorably recreated their famous dance moves on the red carpet. "We rehearsed so much in the three-week period to get it right," Travolta told 'Variety' at the time. "And you can see from the energy on that film, we were so anxious to get it right that I think everything -- it was like going to school. Every day there was a regimen: song, dance, recording, rehearsing scenes, rewriting scenes. It was a big myriad of events." /IANS