Can somebody please explain what is wrong with my code? I still have problems with indendation.

It throws the following error message:

"Your function fails on is_prime(-10). It returns None when it should return False."

Thank you in advance!

```
def is_prime(x):
if x == 0 or x == 1:
return False
if x == 2:
return True
if x > 2:
for n in range(2,x-1):
if x % n == 0:
return False
else:
return True
```