90% of /prog/ cannot write this BASIC PROGRAM

Task: Using your language of choice, implement a program that will a) Prompt the user for 2 numbers, and b) output the number of prime numbers between the two numbers (inclusive.)

Output: A B N

This is my factorial function. Please rate it, I'm new to computers.


fact 0 = 1
fact 1 = 1
fact 2 = 2
fact 3 = 6
fact 4 = 24
fact 5 = 120
fact x = error "uh-oh, the number is invalid!"