Working Girl (1988) on Netflix

Tess McGill is a hard working young woman who is determined to reach the top of the stockmarket world by hard work but as she turns 30 she is stuck in secretarial work so when she starts working for Katherine Parker she is glad that Katherine is willing to accept input and ideas from her. However when Katherine goes on holiday and breaks her leg she asks Tess to look after things and this causes Tess to discover that Katherine is going to pinch her big idea that would save a large company from a a foreign takeover. Enraged that her boyfriend is also cheating on her, Tess sets out to do a deal by using her idea herself while Katherine is away. She teams up with Jack Trainer to close the deal before Katherine's return and the two slowly fall in love little knowing that Jack is Katherine's boyfriend...