Can someone give me a hint? I have a feeling I am close but can't quite figure out what I'm doing wrong.

def word_count (string):    # create a function that accepts a single string argument
    new_string = string.lower()     # lowercase the string and assign it to a new variable
    string_dictionary = {}      # create an empty dictionary
    for word in new_string.split():     # loop through the words in the string(that is split)
        if word in string_dictionary:   # if a word is already in the string dictionary 
            string_dictionary[word] += 1    # +1 to the value of that key (which is that word)
        else:   # otherwise 
            string_dictionary[word] = 1     # add new key (which is that word) with the value of 1
    return string_dictionary    # return the dictionary