ProjectEuler#1 Multiples of 3 and 5

#If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these #multiples is 23.

#Find the sum of all the multiples of 3 or 5 below 1000.

sum = 0
for i in range(1000):
    if (i%3 == 0) or (i%5 == 0):
        sum += i
print sum