Hello I have created this program to check if a number is a prime number. It works but for some reason says that 999 is a prime number. Where is my mistake. It would be great if someone explained. Thank You!

Here is my program:

```
number = raw_input('Enter a Number: ')
nnumber = int(number)
prime_range = range(2, nnumber)

for x in prime_range:

    if nnumber % x == 0:
        print 'Not a Prime Number!'
        break

    else:
        print 'Prime Number!'
        break

```