How to disable/enable UI on key pressed

FAQ :

What are the guidelines for writing good questions?

We want Unity Answers to become a comprehensive database of questions and answers related to Unity. When you ask your questions, it can be helpful to keep a few things in mind:

• Break multi-part problems into simpler questions. Instead of posting a question: "How can I make a gui toggle to change the skybox?", post two simpler questions instead: "How can I make a gui toggle?" and "How can I change the skybox?" This way the questions will also be relevant to people who want to make a toggle for something else, or who want to change the skybox based on something else.

Some reasons for getting a post rejected:

• You haven't provided enough context: we need more information about your problem, relevant code snippets and what you have tried already.

• Your question isn't specific enough: asking for a script, asking multiple questions in one post or asking a question that could be either subjective or require extensive discussion

• There exists duplicate questions with answers if you were to do a search, either on Answers or on the Forum or on Unity's tutorials