title: How do I put error checking into this code, and how do I make my top 3 score function work?
body: <p>So I have an assignment atm which requires me to allow the user(teacher?) to: enter their class (a/b), let them put in the students names, grades, give a grade based on the integer that they put in and then record the grade into a list along with a student. Furthermore, it needs to allow the user to delete a student+value and display the average of each class's scores and then show the top 3 scores for students from both classes. This is where I am current at: <a href="http://pastebin.com/2S7rUqFF" rel="nofollow">http://pastebin.com/2S7rUqFF</a> If you could help with the error checking (eg If the user inputs anything other than an integer for the score, then an error message will pop up and make them re-enter it) and help with the top 3 function (Can't get it to work) that'd be great! thanks</p>