Python 3 break statement

[kresh]

Hi everyone. I have some problem with BREAK in my code. I don't understand why the program does not stop after adding a new username to LIST. Sorry for my question, but I'm a new in Python :) Thanks in advance

#find out an available username
# -*- coding: utf-8 -*-
print("\n===========Sing Up ====================")
print("\nPlease, enter new username:")
print("\n Username:  ")

current_users=['vlad','kate','tania','mike','david']
bad_symbols=('@','#','$','%','^','&','*','(',')','-,'_','+','=','<','>','|',']','[','{','}'',','.','/','?')
while True:
    name_user=raw_input()
    name_user=name_user.lower()
    alfabet=list(name_user)
    
    for alfa in alfabet:
        if alfa in bad_symbols:
            print("\nSorry it is a special symbols, please try again")
        else:
            if name_user in current_users:
                print("\n Sorry,but  " + str(name_user)+"  the name is not available" )
            else:
                print("your USERNAME=" +str(name_user)+"  is approved")
                current_users.append(name_user)
                print(current_users)
        break