[cedricdosss]

Hello, I'm working on this project can someone help me?
Create a world with an astronaut, moon surface, and Lunar Lander (LL). (Web Gallery). Using the “ask the user for a number” function, have the astronaut jump a specific height (but must be visible at all times). The value must be greater than zero, and if not, give and error message and repeat the question until a valid answer is given.

I have the most part, but can't get it to ask again until the valid answer is given.
Can anyone help?
Thanks