Rot-13 Encrypter/Decrypter

[nevets04]

Code:

def rot(a):
    e = list(a)
    q = len(e)
    z = 0
    w = []
    while z < q:
        b = ord(a[z:z+1])
        z = z + 1
        c = b+13
        d = chr(c)
        r = chr(b-13)
        if c <= 122 and c > 96:
            w.append(d)
        elif c > 122:
            w.append(r)
        else: w.append(' ')
    print "".join(w)
    raw_input("Press Enter To Continue")
    menu()




def unrot(a):
    e = list(a)
    q = len(e)
    z = 0
    w = []
    while z < q:
        b = ord(a[z:z+1])
        z = z + 1
        c = b-13
        d = chr(c)
        r = chr(b+13)
        if c <= 122 and c > 96:
            w.append(d)
        elif c > 122:
            w.append(r)
        else: w.append(' ')
    print "".join(w)
    raw_input("Press Enter To Continue")
    menu()
def menu():
    print "1) Encrypt"
    print "2) Decrypt"
    u = (raw_input("What do you want to do?: "))
    if u == '1': rot(raw_input("What do you want to encrypt?: "))
    elif u == '2': unrot(raw_input("What do you want to encrypt?: "))
    else:
        print "Invalid"
        raw_input("Press Enter To Continue")
        menu()
menu()