Temperature Converter (for all temperatures)

[uber1337]

Hey guys I made this for chemistry and I thought I would share
Temperature Converter

Code:

#Credits:
#Nevets04(I can't even count how much of his contributions helped me learn)
#Mr.FeellingLeSS(For the script that clears the shell for XP and Vista)
#Me?

import os
import platform

def clearer():
    systemver=platform.release()
    if systemver=='XP':
        os.system("cls")
    elif systemver=='Vista':
        os.system("clear")
    else:
        os.system("clear")
clearer()

print '***************************** *'
print '*         Welcome!                             '
print '*     To the uber1337                        '
print '*   Temperature Converter                 '
print '******************************'
raw_input('Press Enter to continue')
clearer()
print 'For Farenheit to Celsius, Press:1'
print  'For Farenheit to Kelvin, Press:2'
print 'For Celsius to Farenheit, Press:3'
print    'For Celsius to Kelvin, Press:4'
print    'For Kelvin to Celsius, Press:5'
print  'For Kelvin to Farenheit, Press:6'
x = input('What is it that you want to convert?:')
clearer()
def choice():
    if x==1:
        a = input('Enter your degrees Farenheit here:')
        print (a - 32) * 5/9
    if x==2:
        b = input('Enter your degrees Farenheit here:')
        print (b - 32) * 5/9 + 273
    if x==3:
        c = input('Enter your degrees Celsius here:')
        print c * 9/5 + 32
    if x==4:
        d = input('Enter your degrees Celsius here:')
        print d + 273
    if x==5:
        e = input('Enter your degrees Kelvin here:')
        print e - 273
    if x==6:
        f = input('Enter your degrees Kelvin here:')
        print (f - 273) * 9/5 + 32
choice()
raw_input()