How can I delete a variable after it's been used?

Question

Basically, I want a way to delete X if Y equals 10, so that X cannot be used again until the program finishes.

Answer 1

you can not delete variables in the middle of the execution of program.
variable will automatically get deleted when scope of the variable gets over.

Answer 2

Thanks for the input, I see what you mean now. I wasn't thinking straight, all I had to do was change the variable to something else