Neckbeard translator

neckbeard.py

#!/usr/bin/python

# Debug strings, comment out entry prompt to test the program
string = "Hello m'lady, please do not friendzone.  I am a really nice guy."
string = "M'Hello m'lady, m'please m'do m'not m'friendzone. M'I m'am m'a m'really m'nice m'guy."

def toNeckbeard(string):
    string = "M'"+string
    string = string.replace(" "," m'")
    string = string.replace("m'm'","m'")
    string = string.replace("m' ","")
    string = string.replace(". m",". M")
    string = string.replace("! m","! M")
    string = string.replace("? m","? M")
    string = string.replace(".  m",".  M")
    string = string.replace("!  m","!  M")
    string = string.replace("?  m","?  M")
    return string

def fromNeckbeard(string):
    string = string.replace("m'","")
    string = string.replace("M'","")
    return string

def chkexit(func_in):
    if func_in.lower().strip() == "exit":
        exit()

print '''
    Neckbeard translator
  Translate sentences to and from neckbeard
  Version 1.3.1
  Copyright (c) 2015 maelstr0m, MIT license
'''
input = ""
return_input = ""
while return_input != "2":
    string = raw_input("Enter text to translate > ")
    chkexit(string)
    input = ""
    while input != "1" and input != "2":
        print "Select option:\n  [1] Translate to neckbeard\n  [2] Translate from neckbeard"
        input = raw_input(" > ").strip()
        chkexit(input)

    if input == "1":
        string = toNeckbeard(string)
    elif input == "2":
        string = fromNeckbeard(string)
    else:
        string = toNeckbeard(string)

    print string
    return_input = ""
    while return_input != "1" and return_input != "2":
        print "Would you like to translate another sentence?\n  [1] Yes\n  [2] No"
        return_input = raw_input(" > ")