Define a function Count_Word(W) in Python, where the parameter W is a word (string). The function should read each word of a text file STORY.TXT and count the occurrences of the word W in the text file STORY.TXT (noncase-sensitive search and count). The function is also expected to return the total number of occurrence of the word W in the text file.
For example, if the file content is as follows:
I live in New Delhi
New Delhi is the national capital of India
The Count_Word(‘Delhi’) function should return 2