[Tutor] help

[Tihomir Zjajic]

Please, can you help me convert this code from python 3 to python 2.6
g = input("Enter a vrs_drv:")
vrs_drv = int(g)

def vrs_drv():
    vrs_drv = input("Enter a vrs_drv:")
    if vrs_drv == "21":
        return("1")
    if vrs_drv == "22":
        return("2")
    if vrs_drv == "41":
        return("4")
number1 = vrs_drv()
print("kl_number1:",number1)

def prs_prec():
    prs_prec = input("Enter a prs_prec:")
    if prs_prec == "20":
        return("20")
    if prs_prec == "40":
        return("40")
    if prs_prec == "80":
        return("80")
number2 = prs_prec()
print("kl_number2:",number2)

def teh_kl():
    teh_kl = input("Enter a teh_kl:")
    if teh_kl == "1":
        return("1")
    if teh_kl == "2":
        return("2")
    if teh_kl == "3":
        return("3")
    if teh_kl == "4":
        return("4")
number3 = teh_kl()
print("kl_number3:",number3)

print(number1+number2+number3)
print("\n\nPress the enter key to exit.")

Python 3.1.1 (r311:74483, Aug 17 2009, 17:02:12) [MSC v.1500 32 bit (Intel)]
on win32
Type "copyright", "credits" or "license()" for more information.
>>> ================================ RESTART
>>> ================================
>>>
Enter a vrs_drv:21
Enter a vrs_drv:21
kl_number1: 1
Enter a prs_prec:40
kl_number2: 40
Enter a teh_kl:1
kl_number3: 1
1401


Press the enter key to exit.
>>>



Python 2.6.5 (r265:79096, Mar 19 2010, 21:48:26) [MSC v.1500 32 bit (Intel)]
on win32







Type "copyright", "credits" or "license()" for more information.

    ****************************************************************
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    makes to its subprocess using this computer's internal loopback
    interface.  This connection is not visible on any external
    interface and no data is sent to or received from the Internet.
    ****************************************************************

IDLE 2.6.5
>>> ================================ RESTART
>>> ================================
>>>
Enter a vrs_drv:21
Enter a vrs_drv:21
('kl_number1:', None)
Enter a prs_prec:40
('kl_number2:', None)
Enter a teh_kl:2
('kl_number3:', None)

Traceback (most recent call last):
  File "C:/Users/Tihomir/Desktop/arcpadscript/send.py", line 39, in <module>
    print(number1+number2+number3)
TypeError: unsupported operand type(s) for +: 'NoneType' and 'NoneType'
>>>