I would do it your way it's just that in order to get totalPoints you take the credits a course is worth multiplied by the points you earned for it and THAT number is added to totalPoints http://userpages.umbc.edu/~ofek1/gpacalc.html:
totalPoints = totalPoints + (validNumber * numPoints);
Then the final GPA can be calculated:
finalGPA = totalPoints / totalCredits;
I suppose I'm so confused because I've never had to use objects like document.getElementById to retrieve data, which is what I'll have to do to access the forms. It's also difficult because it's not a fixed number of forms, the user can enter however many courses they're taking???
Btw Fang, you've been more helpful than dozens of websites and Yahoo! answers.