Whats wrong in this python program code? I am facing indentation errors

user_input = chr
user_input=raw_input("Enter your quote")

for letter in user_input:

if user_input.isaplha():

elif user_input[0] >= "h":
    print(user_input.upper())

else:
       None

The code is supposed to check if a user input is aphanumeric or not! If not then havet o check that its first letter is >= h if yes then capitalize all its words