Average calculation Program *need help*

[kobsx4 at gmail.com]

Hello all, I have been struggling with this code for 3 hours now and I'm still stumped. My problem is that when I run the following code:
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#this function will get the total scores
def getScores(totalScores, number):
    for counter in range(0, number):
        score = input('Enter their score: ')
        totalScores = totalScores + score
    
    while not (score >= 0 and score <= 100):
        
        print "Your score must be between 0 and 100."
        score = input('Enter their score: ')
        
        
        
    return totalScores
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the program is supposed to find the average of two test scores and if one of the scores is out of the score range (0-100), an error message is displayed. The main problem with this is that when someone types in a number outside of the range, it'll ask them to enter two scores again, but ends up adding all of the scores together (including the invalid ones) and dividing by how many there are. Please help.