I need help with this problem. I have tried writting the program, i just can not get it to run properly.

Please Write a function qualityPoints that inputs a student's average and returns 4 if a student's average is 90 - 100, 3 if the average is 80 - 89, 2 if the average is 70 - 79, 1 if the average is 60 - 69 and 0 if the average is lower than 60.

and thank you