Jump Problem

Hi @zlxeon , please use the correct code tags, instead of pasting a screenshot of your code. It will make it much more readable and will increase the likeliness that someone will read your code and help you.
You can read about tagging your code here:

Looking at your code, you can add a simple ground check to see if your player is one the ground. You should be able to easily find tutorials like this one.

Hope this helps!