不能在Firefox中使用“ Onblur”

Question

未调用JavaScript处理程序。 在下面的代码中，Firefox无法运行（最新版本）。但是，它在Google Chrome浏览器中可以正常工作

alphabet =['a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z'] 
def caesar(plaintext,shift):  
# initialize ciphertext as blank string
    ciphertext = ""
# loop through the length of the plaintext
    for i in range(len(plaintext)):        
    # get the ith letter from the plaintext
        letter = plaintext[i]
    # find the number position of the ith letter
        num_in_alphabet = alphabet.index(letter)
        print (num_in_alphabet)
    # find the number position of the cipher by adding the shift 
        cipher_num = (num_in_alphabet + shift + 3) % len(alphabet) 
    # find the cipher letter for the cipher number you computed
        cipher_letter = alphabet[cipher_num] 
    # add the cipher letter to the ciphertext
        ciphertext = ciphertext + cipher_letter 

# return the computed ciphertext
    return ciphertext
def main():

    plaintext = ("hello")
    shift = 16

    text = caesar(plaintext,shift)
    print (text)

main()